I think it's a good idea. I fact, when my wife discovered she liked reading books on my NC and I couldn't get near it any more, I got her a Nook Tablet. The HD wasn't out yet. Make sure you register it with the same account and all the books she owns will automatically D/L to it.
Thanks Spider. You helped me decide to go ahead with my decision to go ahead with the purchase of the 32 gig 9 inch NOOK TAB. Her birthday is February 14th so between the tab and the watch which she wanted on Amazon I think she will be satisfied.