DH's brother is divorced with two children. The boy is a teenager and the girl is only 7. The children live with their mother. However, our nephew is in the process of moving in with his father as his mother has been abusive - verbally and physically - and DBIL has applied for custody as a result.
However, for reasons I do not understand, our niece is being left with her mother on the premise that she has not suffered any abuse.
Now, I am lucky enough not to have suffered myself, and not to intimately aware of anyone who has (I'm sure I know people who are abused, I just don't know that they are abused) so I don't know how to judge, but surely if she's abusing her son, she's likely to start on her daughter at some point too? if not now, then certainly when she hits puberty? It seems clear that our nephew's problems with his mother started at that time when he started answering back and generally behaving like an average teenager [although, I also have to say that this is the most mature teenager I've ever met. I regularly worry that he doesn't let loose enough because his parents have put him through hell in the past].
So, IABU to worry about my niece?