Don't worry. The movies are very tame. I've been reading the books since I was eight years-old. The books are dark and get progressively darker, but the movies are tame. Too tame. It outraged the hardcore fans. The darkest was the sixth book. The movie of it came out last Summer. They omitted a lot of the dark stuff and put in a lot of the romantic crap between Ron and Hermione and "Lav-Lav." I wouldn't worry about age at all.