Adoption Support Group
Adoption is the legal act of permanently placing a child with a parent or parents other than the birth parents. Whether you are looking to adopt, putting your child up for adoption, parenting an adopted child, or just thinking about it, this is the place to discuss.
I am glad to see that you included several possible ways to make the initial contact with your half siblings. That is wise. I would encourage you to compose a brief letter and send it to each of them simultaneously.
In order to make the decision about what to say, I would encourage you to try to put yourself in their place and think about the many questions and feelings that such a letter may raise. That will give you a starting place to consider what to say that will not set off alarm bells for them, which might result in a rejection of your invitation to have further contact.
You might, for example, consider saying that you have done some genealogical work and believe that you may be related. Ask whether they know or have suspected that there is a family member whom they have never met, related through their mother. Express hope that they may be willing to confirm the family connection as you have never had the chance to meet or have information or photos of your ancestral family due to the fact that you were relinquished for adoption. That you have been searching in hopes TO fill in the missing pieces of your personal history-- something that has been a long-standing need and desire that you hope that they may be able to understand.
I would provide information about how you found them and what makes you believe that you are related. Provide information about what you would like to know/have (i.e. medical history, photographs, details of their mother's life, etc...) and let them know that you will be respectful of their lives, and that they may need time to think about this before deciding how to respond. Tell them, too, what you DON'T intend to do-- disrupt their lives, ask for any part of anyone's estate, etc..... Putting that into writing may allay some of their fears, if they have them after reading your letter. Also tell them a little about yourself, giving the kind of information that would provide some reassurance that you are a stable person who would pose no threat to them or their respective families (if they have them). Consider including several photographs of yourself at various stages of your life thus far, and ask that they look at them to see whether or not there may be a resemblance to other family members.
Invite/ask them to reply, and offer some ways that they might do so. Provide your mailing address, your e-mail address, a phone number. You might also offer the name and contact information for someone you would feel comfortable fielding such a phone call-- a counselor, a friend, a clergy member (if there is one whom you know and would feel comfortable with), for this would convey to them that you are wanting to be respectful of their privacy, should they want that, and that you really want to provide a way for them to feel comfortable, should this come as a shock.
Sometimes biological family members are intrigued, or they have knowledge or suspicion that they have a sibling/family member who is unknown and are very eager to make contact. You are correct, however, that sometimes this comes as a major shock. When that is the case, the individuals may take their time processing the information, making guesses about how you might be related, or do a little investigating of their own prior to replying. Unfortunately, some are not willing to reply and give information, at least at first. That can be very frustrating and disappointing, of course, so it would be a good idea for you to have a support system in place, for yourself. Search, as you have, no doubt, already realized, is not for the feint of heart.
Another terrific option is to have an adoption professional (adoption social worker or therapist), or a counselor, or a member of the helping profession (clergy member, nurse, etc..) make an initial phone call and share the information you would want that individual to convey. Ask them to provide your contact information or to offer to be an intermediary, at first.
I wish you well, NJ. Your online-name stirred memories for me of when I grew up (in SE Pennsylvania-- just across the river from Trenton, NJ) and my family acted as foster care providers to babies and toddlers whose original parents were considering whether or not to place their child for adoption. It was that early history for me that eventually led me to the work that I do as an adoption therapist. My parents were foster parents through Children's Home Society of New Jersey. Anyway, I hope that your inquiry is warmly welcomed, that you are able to confirm that they are your half-siblings, and that you are able to launch a satisfying relationship with them. Good luck!