Some of the PP are suggesting that you leave this woman immediately. I disagree. You and your dd have already been through a divorce. Marriage takes work and lots of communication. If you leave this relationship, what would you do next? Be single until your daughter is an adult? Try to reconcile with your xw? Find another woman with children (a whole other can of worms)?
Yes, marriage takes work and lots of communication - and two people who follow a minimum of respect to each other and the kids. The OP's wife has shown that she is capable of REALLY inappropriate behavior that is directed at and harmful to a four year old child that she supposedly wants to mother?
What would he do after the divorce from the woman who is abusing his child? (and I don't use the word abuse lightly) Be single. Find another relationship. Regardless, I can't think of any situation that would be much worse than the current one. ANYTHING would be better for that child than living in a house with a woman who is clearly not well. She needs help. But even with help, there is no way in the world I'd trust her around kids again.
In only 5 months, how much conflict resolution can have occured? I know a lot of people are pro-divorce, but even without bio children, the effects will last years. This isn't his GF, it's his wife. He decided he wanted to marry her, so she must have other qualities that he loves.
Do you think the OP came to this forum looking for validation to divorce his wife? Or perhaps suggestions on how to get through to her and change the situation?
Her witty sense of humor, her good cooking, their common interest in old movies - doesn't overshadow abusing his child! I cannot begin to understand how you think otherwise.
And you're right - he clearly came here looking for advice on how to fix this issue. But that was before the last weekend happened. My opinion as I read through the thread was to get the wife into counseling and possibly anti-depressants, and maybe an online infertility support group. But after his post about the last weekend, it is crystal clear that he needs to keep his wife and child apart. The child isn't safe with the wife. And if he stays with the wife but sends the child to her mom's - well, that looks an awful lot like choosing the wife over the child. I'd move out so my child had a safe home with me for the part of the week she was with me.
I was horrified by the stepmom making her sd call her mommy - before I read how much worse it got. Also, why does the stepmom think the bio mom is SO bad? Does she have a leg to stand on there - or just going off the deep end?
OP, what an awful situation. You sound like a really great father and all around good guy. I'm sorry you and your dd are going through this.