Harry Potter Boxed Set discussion

I am a Harry Potter fan since I was 6. Now I am 19 and still I am Potter obsessed. I wanted to gift the entire series to my cousin who is again my age and I am not sure if she would enjoy these books the way I do.

So, according to you guys, what do you think is the correct age to read Potter or rather till what age can we read harry potter series?

I think the correct age would be at least 10. At 6 I was a big reader too. But most people read big books at 10+. But I also think any age above 10 would enjoy this book. I only say 10 because my sister was 9 when she read it and had nightmares. Also, my friends read it at 8,9 and had nightmares. Which I personally don't get. I'm a Potter Fan!