i can but it depends on what exactly you want the 12yo to learn/understand. so for example a convo on puberty or a convo on menstruation or nocturnal emission or intercourse or sexual orientation will be different.

i think a good place to start for general overview of puberty and body changes and adolescents is brainpop.com (they also do HIV but are more on the science tip than the sociology tip). they do require a registration and a fee, but they also offer a 2 week trial period. there are videos and quizzes for youth to interact with and I used it often when I taught middle school.

then for a more sociology/pop culture discussion/presentation I'd suggest scenariosusa.com (i think or .org) they have all their videos online and they are written by youth and then the youth are partnered w/world leading directors to make their film. I like the films "from an objective point of view" re: abstinence and "it all falls down" regarding decision making and dating. they have lots of films representing various youth of different identities.

if you have something specific in mind send me another question and i can tell you what i know of. hope this is helpful!