Kerfuffled AND Mad, Great Mix!!

I just don't get my sister in law lately.  I mean, she has had a bumpy go of life, but seriously!
Back story, she started dating a guy in highschool, her parents didn't approve.  At 18 she got pregnant with his kid.  She was kicked out, didn't graduate, ended up moving back home after her first son was born.  Kept seeing the same guy, got pregnant again, had her second son while still living at home.  Eventually she moved out when the second son was young, but the older one was three.  So they(her parents and her) decided the older one would stay with them until she had her roots down because it was the only home he had known.  So she moved out, and the same guy came with her.  In the end her oldest son never came to live with her, and her youngest son somehow came to live with her parents too.  She had two more kids, so a grand total of four, with the same guy.  The two youngest are girls and live with her.
She is no longer with the guy.  He was a chronic cheater and he has other kids with other women.  She doesn't work as she has been deemed depressed and she is meant to be taking pills but she doesn't.  She is also living in low income housing, it's a program where they charge you rent based on your income.  They have 'low income houses' and she got an actual house recentley when before she was living in a townhouse through them.
She has started doing pot, ALOT of it.  Her kids get passed off on a family member every weekend, the two she has anyways.  She came here one night, at 8pm, and her daughter hadn't even had supper yet. 
She got 'paid' yesterday, child tax, family tax and whatever money she get's from the government.  And she messaged Joey last night because she want's to borrow money!  Last time we leant her money we found out she bought pot with it, then asked us for MORE money because her kids didn't have food.  So we took the kids and went grocery shopping.  Never saw that money.
Now she texts me to ask if Joey told me about that money he was going to lend her.  Well, Joey hasn't mentioned it to me.  And I told her as much, and she asked if I could just give it to her anyways.  I told her no, not before I hear from Joey on the matter.
She was Marlow's babysitter while I worked before, and we paid her, but she became way to unreliable and I stopped trusting her.  We won't even let her watch Marlow while we go to a movie anymore.  I worry for the kids she has.
She got picked up by the cops, as she was ratted out for smoking weed.  They offered her money to rat out her dealer, she said no and they had to release her.  But now they will be watching her like a hawk, if she gets caught they will hold jail time over her head to get info.  And her parents will take her last two kids, she will get kicked out of low income and lose her subsidy.
I really don't know what to do.  There has been a big rift between her and I since the whole going on a trip and leaving her in heat dog here three times as long as she said.  We don't do things together like we used too.  We used to go get our hair done together, and the other day she asked Joey if I wanted to come if she could get ahold of the hair dresser.  I said sure, then she claimed for weeks that she couldn't get ahold of her.  But yesterday she showed up with her hair cut, dyed and styled!  The hairdresser is a friend of hers, so she was my only contact to her, guess it's time to find a new one. :(
She has a dog, and a rule of low income is you aren't allowed pets.  But her kids love that dog, so I won't rat her out.  She had a kitten too but she got rid of it.
Her house is always a mess.  It often smells.  Their is food on her floors, stuck there, and her sink is always full of dishes even though she has a dishwasher.  Her garbages always overflow and there is always dirty clothes and garbage strewn over everything.  I hate going there.
It got better when she moved and left the guy she was with.  But now it's gotten way worse.  And, we find out, she has still been sleeping with her ex!  Oh, and his brother now!  Then she ended up pregnant, but she lost it.  And she didn't know who the dad was.  On top of that she has been meeting men off the internet, and often sleeping with them.
It's like she has gone off the deep end, and I don't know why?!?  Her life was rough, sure, but that's really no reason to just go for a loop.