Anonymous wrote:Look at used bikes at REI and elsewhere. A new lightweight bike will be a lot more expensive than the same bike used.
I love REI in general, but I would go to a bike store that has a used selection for this purchase to make sure you're talking about someone who really knows bikes. We got a decent used bike at Trek in College Park. I would not buy new or very high end for a commuter bike that presumably would be left outside.
Another option would be to ask her friends to try theirs to see if they're comfortable. If they're roughly the same size.
I had a friend who wanted a "faster bike" who came to the realization that her bike was fine and she was just out of shape!
Lastly her existing bike may ride better with a tune up, so that could be a cheaper interim step, especially if you haven't been doing regular maintenance.