There are very minute differences between Canon and Nikons for anyone except the most discerning photographer. The truth of the matter is that fantastic shots were occurring with digital cameras 10 years ago, on what is considered worthless technology today. The real quality of a photo comes from the photographer's understanding and ability, not necessarily the quality of the camera. I am no photographer, but I do really like my Nikon D5300.
For the quoted price range, I would look at the 3000 series. Costco has a GREAT beginners package, but the "kit" lens is garbage and the telescoping lens is OK, but both are more than suitable for the learning process which is why I suggest this package. You can always sell off these lenses and grab something like a 50mm f/1.8 prime lens for about $200. This, IMO, would take care of a large majority of photos. Most people never take this lens off their camera!
The last option is to take a risk with a used camera, something like the D5300 or D7100 may be in your price range with a decent lens or two.
Here is the Costco option. You can look all over cyberspace and find nothing that comes close considering Costco's warranty, reputation, etc. All the other deals out there have a bunch of crap you'll never use!
http://www.costco.com/Nikon-D3300-DSLR-Camera-2-Lens-Bundle.product.100107159.html
Good luck, she is a lucky woman.
