OP, ignore those who say you’re too judgemental. And those saying you shouldn’t be too harsh because the mother may have been abused herself. That comment is frankly insulting to victims of child abuse who don’t grow up to be child abusers themselves.
Many horrible people were abused as children. Doesn’t give them any right or excuse their growing up to abuse their own children or others. Do we extend the same empathy to the likes of Fred and rose west? Myra Hindley? Harold shipman? And the list of depraved characters goes on.
This woman put a rapist over her children. To the extent she gave them up to be with him. That’s not worthy of any sympathy, it doesn’t matter what kind of childhood she had. Most people who were abused as children don’t grow up to be abusers themselves.
My DP grew up in foster care and many of the other children he was fostered with, and who had been adopted by his foster parents sought out relationships with their birth parents. They were supported in doing so by the AP, and invariably they have come back. As DP’s brother said, “what they often forget is that there was a reason why they were adopted in the first place.”
I know at least one of them essentially uses her birth father for money. She feels he owes her, but has no more of a relationship with him than that. And the rest have all realised that the grass isn’t greener.
Ultimately as your DD is an adult she has to forge her own path. And the truth is that most adult children will make some decisions that their parents are uncomfortable with, but this one is so much more difficult to reconcile because of the emotion behind it.
All you can do is be there. I like that saying, if you love something, let it go. If it comes back to you, then it’s yours forever. If it doesn’t, it wasn’t meant to be.