I (24yo female) recently started seeing a therapist, and she asked me about my childhood. Unfortunately, I barely have any memories before 10yo. I know that I have been feeling depressed and empty since, but I never knew why. 
She gave me this form for my parents to fill about childhood behavior.
While discussing with my mom, she told me a disturbing event.
When I was 6yo, I told her that my cousin (15yo female) touched my vagina and that it felt weird. Apparently, I wasn’t shocked when I told her this.
Was it sexual abuse knowing that my cousin was also minor? I have no memories about this, I don’t know if she just quickly touched my vagina and didn’t go further but it still feels wrong.. 
I am confused because my mom never told me about this and it felt like she was minimizing it. So now I am confused if this is sexual abuse and if I could have trauma about it.
I feel like I have been dissociating way more since learning about this event.
I was thinking about trying hypnosis to recover childhood memories but I am terrified because I feel like there is more horrifying things that I completely forgot. Any advices or similar experiences?