My mom keeps saying my daughter could be lying about being molested

I have a 3 year old daughter who was recently molested by someone we know. She literally told me "Curtis stuck his fingers up here." Talking about her vagina. There's an investigation. My mom has been telling me how do I know this happened. Why didn't I talk to Curtis? When a 3 year old comes up to me and says a grown man stuck his fingers up her vagina I'm not talking to the grown man. She has been saying my daughter could be lying. We don't know. He could be a good man and I could be ruining his life. I said "Like how you though Easton was a good man." Easton was our babysitter who ended up molesting my brother. My mom got mad that I brought that up. There were so many signs that Easton was a creep and he has been accused of molesting little boys before. She still hired him. My mom is upset but I got tired of her trying to convince me my daughter could be lying