Will he molest her too?

My big cousin who is 11 years older than me molested me for years growing up, and had sex with his step sister who was younger than me when she was 13 and he 23 freshly married. I told my family about it but they blew it off many times even tho I have brought it up many times over the last few years about not wanting to go to family events if he is there. Which he always is and then they say things like "why don't you bother to come to family events" like 🥴🥴 anyways... he had 3 kids with his wife. One daughter who is absolutely gorgeous, one of the prettiest little girls I have ever seen. I'm not aloud near his kids and I've tried so many times to try to talk to his daughter in private and say something like "only your husband can see those parts down there unless you're getting bathroom help" but I'm never able to get the chance. It makes me sick knowing he might or is molesting her, and allowing her to go down on him, etc. I was molested by him from my earliest memory(idk what age) through 1st grade. I remember doing terrible things to him and some times I can't even live with the memories. Do you think he is or will molest her to? Do you think he's changed since I've brought it up to our family? Or once a rapist always a rapist? I just seen her the other day, his daughter, my aunt brandy(his mother) was watching them. They said the 4eason he molested me was because he was a horny teen and didn't understand it was wrong. But he was old enough to drink and was married when he had sex with his sister. It was "consensual" and I walked in on it. Advice really needed. I want to approach his wife about it but is it my place?