My son is about the same age as Howlers. But DS17 wasn't reading long chapter fiction by himself at quite as young an age as her daughter. (He was an advanced reader, but wouldn't read long chapter books till a bit older.) I read most of the books to him around between 6-7 years old. I dragged the last few books out only reading HP6 to him a few months before the last book was due out. There was HP fever, everywhere including our house and it would have been very difficult to keep from him. But I wanted him to have read (or been read to) the books before seeing the movies. My husband was a HUGE fan before either me or the kids. The last book & 6th movie came out around a family trip to Europe when he was 7. We saw the 6th movie in London, went to Kings Cross station etc.. And I read DS the 7th book shortly after it was released. (I had to read the entire thing to myself first.)

And then when DS was 12. He spend a month long vacation, reading the entire series cover to cover and obsessing about the books in a way he didn't when he was 6. I ended up buying used paperback versions of the books for that trip.

If HP fever hadn't been such a big think at the time my son was 6 & 7 I probably would have put off reading the later books to him till he was a bit older. This is my child who still freaks out about Charlie & the Chocolate Factory and I have NO idea why HP was OK, watching ET was OK, and eventually the LOTR movies before he was 10. But still can't stand ANY version (book or movie) of Charlie & the Chocolate Factory.