Re: Films - meh
Well, your 12 year old was the upper limit of the target audience, certainly for the first [hharry Potter] book.
That's a weak excuse. There's a great deal of good children's and young-adult fantasy which remains entertaining and interesting for older readers.
I don't begrudge Rowling any of her success. The books aren't pernicious, just lousy. Rowling gave people something they wanted, and she got lots of folks reading for pleasure who otherwise might not have.
But, man, those books are bad - at least the first, second, and fourth, which were the only ones I managed to read (and I read a lot of children's fantasy). Simplistic characters, uninspired prose, and plots that depend on the unimaginative use of magical devices which if employed properly or consistently would have overwhelming consequences. The whole Harry Potter world is inherently broken.
(Some months back I read Rainbow Rowell's Fangirl and was amused to note that the protagonist's fanfic, for a fictional HP-style series, was considerably better written than the actual Potter books.)
I hope at least some of the hordes of HP fans eventually go on to better children's / YA fantasy. Like, say, Turnbull's The Frightened Forest. Or McKillip's Riddle Master trilogy. Or Hopkinson's Brown Girl in the Ring. Le Guin's Earthsea books. Mieville's Un Lun Dun. Okorafor's Binti. Moriarti's Colors of Madeleine series. Bacigaluipi's Shipbreaker. Gaiman's Stardust, Neverwhere, The Ocean at the End of the Lane. (Those are published as adult novels but are perfectly accessible for children.) Valente's The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making, which deserves to be read on the strength of its title alone. Pratchet's YA books, particularly the Tiffany Aching ones. There are so very many examples of terrific fantasy novels for children.