Just get an iPad. I mean it's already got Winnie the Pooh, and that Alice prog. And iBooks has that awesome pageturn animation that mystifies all the reviewers.
Just kidding.
I too recommend the jetBook/Libre group or one of the 5" e-ink readers. In this quite rare situation, I'd recommend the E-Ink devices for battery life and also because they can handle DRM-enabled books with less fiddling than the LCD-based devices would demand. I'm no fan of E-Ink, but for a child who probably has linear reading habits, it should be good enough. It may also help teach something of patience.
