My Girl is 16 now , wouldn't worry me. It's only natural for her to be curious about Sex at this age.
I'm very open with her about Sex , won't keep her in the Dark like my mum did with me.
My Sex ed was a healthy mix of Catherine Cookson, Mills & Boon and other soppy fluff from my mums bookshelves that taught me all about Romance
Dads contribution ........Penthouse , Razzle and Mayfair........... stashed under the bed..........which taught me ... *cough* ..... less said about that the better .....lolz