Im not too worried, she either knows what they are talking about already (worryingly more than I would have done at 11), or she just won't get it.
The reason I won't let her watch TW yet is more for the violence (MD ep 7 springs to mind) than the sex. (not that I particularly want to get into a discussion about orgasmic energy yet if I can help it!) - gives her something to look forward to in a couple of years. I'll probably watch episode 1 season 1 with her though so she knows who's Kai's character is.
I think she'll enjoy it, she is fascinated by the process of film making and she is used to having her Dad and I pointing everything out so this is bound to be more interesting lol!