HELP I NEED ADVICE

my daughter who is now fifteen has recently been having trouble in school having nightmares and just your lack of concentration we went to counseling and she reported that my ex husband not her father was molesting her from the age of 6 to 9 I'm very upset that I didn't know what was going on and then I didn't protect her now the question is do I press charges I talked to her about it she says she's strong enough to go through trial and court if that's what needs to be done my fiance now who is that absolute wonderful loving caring man thinks we should let things be and let God do the judgment I feel like I feel there once I don't want to feel her twice what do you guys think