Looking for advice on sibling relationship

Hello, I'm new to the forum. And I am having trouble with this. When I was 13 and my sister was 8. I was in her room and I asked her we could cuddle, which we did. I did get aroused, but we did not take our clothes off, I didn't touch any of her body parts, we did not kiss, it was just a brief cuddle which felt good. This never happened again, and we've always had a good relationship as siblings.

I'm 64 now. I never really felt guilty about it or had issues with it and the memory of it sort of faded over the years. Recently I was in therapy and mentioned this to my therapist and she didn't think that much of it. So it really hasn't been an issue. Recently I was together with my family and my sister's husband mentioned that my sister doesn't remember some of her childhood, that he thinks she had some sort of Trauma. It wasn't directed at me but at the group. Right away I felt super guilty that maybe some how I caused the trauma

We did have other trauma in our lives. My sister was in a bad bicycle accident with my cousin where she flew over the handlebars and was injured. We also were in a bad accident in a trailer when we were teens where both my sisters flew out of the back of the car. Luckily nobody was killed.

I am very reluctant to bring this up with her because she may not even remember it or it may not bother her, and I didn't want to put something in her head that maybe isn't there. Her issues could be totally unrelated to this. Looking for advice on the forum.