She was honest with you. I'm so sorry. I can imagine how awful it was to hear it. The only good thing is you have intel. This is about other men so the advise seems to be harsher. What have you been advised by attorney? I would not support your wife any more than you legally need to. But I would never withhold anything that would benefit your daughter.
I believe the advise is typically to cut her out and let her deal with her own problems. Don't be nasty or show her hostility but don't be her friend either. She kind of needs to hit rock bottom.
It's so awful and hard and nothing any of us can say will change things, but there is not much you can do. Just keep being an awesome dad.
Can I recommend you read tiger eyes entire thread, if you haven't allready? He seems like a guy that really embraced GAL through a lot of hardships. I think it will make you feel better.
Keep posting.
Me: 42 H: 43 Twins age 5 Physically Separated 7/2015