Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.
Trying to involve other family members can be really dicey. What ends up happening is a "triangulation" where suddenly the sister feels "ganged up" on and then will likely lash out in worse ways. Simply tell her that you will have to limit your time with her because you can't deal with the way she treats you. If you have children and she is the "favorite aunt," this will be a big deal for her.
The bottom line is you DO have a choice in how much contact you have with her. If the family dynamic has it that you are all vying for the attention of your parents, then some serious sessions of family counseling could be in order.
I know that it is not easy. It has never been easy in my family, and we have the benefit of living all over the country (most of us anyway.) I don't know that any of this helps, but I just wanted you to know that there is someone (and I suspect there are many others as well) who have similar problems with their family of origin.
What makes me really mad though is that whenever it happens, my mom will call a few days later and say, "Dad and I do love you." and I always feel like asking, "Then why don't you show it?"
I know there is no advice in my post just wanted to let you know that there are others who know what you are going through.
Ex: My siblings are both younger than me, I'm 21, sister's 18, brother's 16. I got my permit at 16, really started driving at 18; my family has three licensed cars and a company car for my lazy father, which makes 4 cars and 5 family members (mother & brother too). Brother got his license at 16, sister got her license AFTER him at 18. So this means dad's driving company car, mom's driving "new" car, I'm driving car #2, and brother's driving old car by the time she gets her license.
Now, she's not allowed to drive mom's new car, so that leaves cars #2 and 3. Car 3 is too old for her, so brother gets it all to himself (I don't trust the damned thing to get me where I'm going - usually a larger distance than where he's going) which leaves car #2. So she starts driving the car and taking it whenever the hell she feels like, waking up 10 minutes earlier just to get out to the cars before me, and shit like that. Turned in to a real jerk about it.
Well, I got tired of it and said "school before work, I'm taking the car, shut up." and she started complaining about gas, which I took note of and paid for Precisely! how much would get me to school and back, and eventually she just made me so angry I wanted to hit her. She wouldn't listen and CERTAINLY wouldn't cooperate.
So one morning she walks into the bathroom (6:45am or so -- I'm a night person!) and tells me she used the last bit of gas I had left in the van so I would be able to get to school. I sighed or something and she made a snide remark like, "Yeah, tell me about it," and I thought she closed the door. That's something she would do, just to have the last word, and it only made me angrier. I screamed "F--K YOU!" loud as I could to be heard over the shower and through the door. (this was before I was completely awake with my tact skills hadn't kicked in yet) Well... She had still been standing right there and screamed back something, I don't even remember what now - I don't remember because I was standing there in shock that I had just done that. So I stood there and wondered if I should feel bad about it or apologize and I realizes that it felt really, REALLY good to have done that and NO I will NOT apologize to her!
Since then she hasn't said a single word to me in complaint about gas, has discovered the meaning of "cooperate," and lightened up on the being so unpleasant to me.
I'm not suggesting go curse your various difficult sisters out, mine was more or less a mistake. (Had she caught me 10 minutes later I would have had a different response.) But! People will push you, family or not, until you say "When!" and you have got to learn how to do that. When you firmly and definitely show that you will NOT stand for any more, you'll be surprised at the reactions. Siblings push each other because in growing up they've learned that it always works. It always had and it always will. YOU must change that. YOU have to be the one to say you will NOT be on the receiving end anymore. I can't say what would help you any more than I can say how your sister would react to my situation, but it IS within you to find out what works.
Consistent, patient refusal to be the bad guy might be a much better path for you, who knows.
This sort of dynamic sucks and is certainly 'dicey' as one user put it. Sibling abuse severely distorted my self-perception relative to my immediate family; as I grew up that messed-up mentality underwent a sort of metastasis ultimately infecting every facet of my life. Relationships with friends, partners, colleagues, and naïve extended family members all suffered. Even now, when I believe someone is upset or about to be angry with me (even simply disagree), my body goes into a state of panic. There is a total disconnect between knowing that I'm not in physical danger and feeling like I'm about to have the shit beat out of me. It's sad, but when I think it that way, it mostly annoys me due to how much it's really hindered my ability to hone inter/intrapersonal skills.
Below, I've listed some advice/tips/strategies that professionals and friends have offered me over the years. I have had some success in implementing them. For me, consistency is key to changing my family dynamic. I hope it helps you (though it may not be appropriate for your situation).
1. Seek professional help.
Even if you manage to distance yourself from your abusive sibling, psychological scars run deep. The behaviors and thought patterns that helped you survive abuse at home leave you ill-equipped to form healthy relationships as an adult in the outside world. If your therapist/counselor/social worker kind of sucks, treat sessions as a safe space to find support and speak up while you look for a better fit.
2. Try a support group
Sometimes these work, sometimes they don't, sometimes they are not what they seem. My abuse manifested as a severe eating disorder. I went to an EDA (eating disorders anonymous) meeting not really knowing what to expect. To my surprise, a lot of stories involved abuse at home. While no two situations are identical (and even if they are, everyone's individual experience is unique), I still found that we all had an immense amount of empathy for one another. If you're reading this, you already agree it's an idea worth exploring.
3. Set and maintain boundaries
If you live under the same roof and your parents/guardians fail to intervene consider reaching out to friends to discuss temporarily relocating to their house. Speak to their parents or give your friend permission to talk to their parents about your situation. Share what is comfortable, but get the point across that you don't feel safe at home. Consider it a form of self-care while you work out more long-term solutions.
If you do not live with your sibling, you still need to establish boundaries. Writing my family off is not a realistic (albeit tempting) solution. My mom lives in Asia (my family lives in the US), there are weddings, holidays, and my innocent, adoring baby niece. So here is what I did for family gatherings:
A.) Set strict time limits
B.) Bring a highly-trusted friend/partner along who is both privy to the situation and relatively unfamiliar to my sibling (so she cannot fully anticipate the result of her acting abusively towards me in their presence)
C.) Stay at a hotel/motel/air bnb (NOT with family)
D.) Rent a car/have the trusted friend drive and goes with me (NO carpooling with family)
E.) Have the number for the clinician on call*
F.) Set visits with my niece according to A-E and/or try to create one-on-one time with my niece at large family gatherings where my sister is relatively absent (by being distracted with others)
G.) Do not communicate over social media (I don't do this, but maybe others do)
H.) Do NOT entertain inquiries (no matter how well-meaning) about the details of A-F. This isn't necessary for anyone to know but you. Of course to set a plan, I will provide the meeting time/location, but nothing else unless I genuinely want to share (without solicitation).
I think the worse thing about abuse is that you feel you have no power, no right to take care of yourself. You're a victim and you're trapped and that's just the way it is... but in the wise words of an old friend of mine, "Fuck that noise."
My goal is to get into a healthy-enough headspace to let go of my sister's most recent abusive episode and apologize (however absurd and completely backwards that feels to me) so that she is left believing that she has won or regained control (what all abusers seek) or whatever it is that convinces her to then say yes to me spending quality one-on-one time with my niece (somewhere separate from my sister's house... like the aquarium or a restaurant...and withOUT my sister present). Yes, my apology will be insincere and no I do not forgive her for her last episode and the decades of abuse that precede it. I have zero interest in being her friend. My goal is to keep building a healthy and happy relationship with my niece. Reminding myself of that helps me to psychologically and emotionally separate myself from my sister, not just physically (like I do in my list above). Working towards this helps me feel safer as I know her power over me will become less and and less and eventually nothing. This does NOT mean I will accept her abusive behavior towards me or that I would put myself in a potentially dangerous situation (see A-F).
*For clinicians on call: I would plan this with my therapist prior to a visit with my niece/family event. At the time, I was in university so I would call the school's psychological and counseling services hotline which connected me with a psychologist/psychiatrist on call (in case my therapist was not available). I work at an academic medical center now and believe the same option is available through the employee behavioral health services benefit. I can't speak to non-academic centers. If none of those options are available to you, call a hotline (this was what I had done prior to ever seeing a therapist, they ended up finding me a local support group too).
Here is a link: https://www.healthyplace.com/other-info/resources/mental-health-hotline-numbers-and-referral-resources
I hope you find peace.