I've got a Galaxy Tab and just recently upgraded my kindle keyboard to a kindle paperwhite. The difference from the first kindle to the new one is quite huge. The font is much clearer, and having the backlight is a huge benefit. I do use the galaxy to read magazines since I've got some on nook, some on kindle and some on zinio so having them in once spot is nice.

If she's just doing books the kindle, specifically the paperwhite, is worth a look. (Amazon is showing a ship date of 4-5 weeks, but I was able to find mine at a local best buy, so your mileage may vary)