possible molestation... HELP!!

My god daughter who is also my niece recently came to me and reported that my Aunt Loris has been molesting her. Normally when a child comes to me and says this I immediately report it whether they’re my patient or not but the child’s history makes me question some things. Around the time when she was 13 she falsely accused my *adoptive* dad of raping her but accusations were quickly dismissed as the time frame given he was accompanying me and my brother on our trip. Then when she turned 15 she would randomly lie about different things from being pregnant to being homeless. Now she’s 17 and some people would probably chuck this up to being another false accusation but the person she mentioned made me hesitant to believe she’s lying. Quick backstory: my biological mom was stabbed to death by her then boyfriend in front of me and my siblings so my aunt Ann and aunt loris took all 9 of us in but shortly after my aunt loris started to molest me and my other aunt didn’t believe me but my aunt loris’ son did so I moved in with him and his baby mother and they adopted me and no one but my adoptive parents and my therapist know this so I know she hasn’t heard my experience. 

So what do I do? I know how it feels to have this swept under the rug but I’ve also personally forgiven my abuser and would hate to ruin her life with this accusation for it to not be true.

**To those saying to help find her another living arrangement she doesn’t live with my aunt she lives with both parents and actively chooses to go over there multiple times a week which is another reason why I’m hesitant. just realized that it may be an important part of this situation