You have 2 choices, first, you can let her go and find out the hard way, or, you can file for full custody before she does. What could help your cause, and your daughters cause, if a phone call to child family protection services about the wife's current parenting procedures and have them do an inspection of her life, for the protection of ALL the children. Your daughter will most likely fight you on staying with you and it will be hard for both of you but I know for sure that she will thank you some day for saving her. Stop worrying about her hating you now, once the mother's life crashes, and it will, your daughter, hopefully will see who was right.