I have a post I want to write about adoption and raising M to feel as whole as possible, understanding that it may not be totally possible. But for now… Just an update on my search for contact with M’s bio family. I got a message from her sister’s step mom, the same sister we met a year ago. She passed on her number and her husband’s number. I got ahold of the husband and asked her to call me back, so there’s that. Her sister is now four, and the next oldest of the four half siblings that M has. I am not getting a response from the brother’s dad and only have his face book.
M’s birth mom opened up her fifth Facebook account in September. I just found it and wrote her again.
Finally, I sent messages to her aunt and grandpa, both of who live in our town and have facebooks.
Mother of All Things 
Has her birth family shown interest in meeting you all and keeping in contact? It sounds like the step mom of her half sister has.