If you're interested in going the used route, check out this link -
http://tinyurl.com/9ynzf - click on your city and then on bikes. Probably a lot of used bikes in your area will be listed. Of course, all the "buyers beware" advice applies. Still, if I was to buy a used bike, I'd want to get one in an area where I could check it out first before buying.
Heck, you could even try to sell her bike by the same means, which would even lessen your out-of-pocket expenses.