I started very early with mine. During snuggles he would teach me how to feel good and help him feel good. I don’t regret it and sometimes use the memories to help me get off
It's best to err on the side of caution. 12 is such a young age. You don't wanna literally rip her pussy apart if you are a good breeder. I waited till my stepdaughter was 16... Just to be safe.