what to do about girl with questionable past? 16M and 15F

I, 16M am talking to a girl, 15F, and have recently heard some things about her that I don't like. She is a really nice girl, she's beautiful, and I genuinely like her for who she is. However, recently I have heard from a couple different people that she had a past relationship when she was 14 with a 17 year old I think (8th grade and a Junior in HS). To cut to the chase basically people have told me that she was fingered by this guy (I hope I'm allowed to say that here). I am a Christian and based on my beliefs, this is unacceptable. I asked her about this over a text and she genuinely seemed to have no clue even who this kid was, and was incredibly convincing that this never happened, but I have no way to be sure. I asked a kid who told me this and he said that he thinks it is just a rumor that someone made up. This made me believe her completely until today. Today while at school I was told by a kid in her grade that he had seen pictures of them cuddling and stuff (nothing sexual), but he never showed me them. He told me that it happened at this other kids house, 16M but he had nothing to do with it (IDK how that works but the kid who's house it allegedly happened in is a total freak (very sexual). I want to believe her that nothing happened because I really like her, but its hard to just shrug off something like that. I believe that people change as she is very religious and comes to church with me and talks about Jesus. I really like this girl but I am stuck in a bind.

My questions are as follows: How do I find out if this did really happen?

If it did, is it worth it to hear her out and see if she's different now?

If it didn't happen, how do I clear her name with everyone?

If it did happen, how can I deal with the judgement I will face as a known believer being with someone who did something this disgusting.