I told my dd10 the full version of the facts of life when she was 8, because she was going into a 4/5 split and i knew there would be kids in her class 2 years older and she would likely hear things. She was very calm and handled the information well, with what i thought was an approprioate amount of "ew, that's gross" in her responses. DS9, on the other hand, gets all cringey when i bring it up, saying he doesn't want to know. I'm playing it by ear with him and will likely sit him down and require that he listen at some point. I'd rather that my kids get accurate info from me than who knows what kind of info from the play ground...