Well, I'm near your mother's age (59 next week), and 2 years ago I did about the same. My sister (Trek420) wasn't there to advise me, so I wound up buying a bike that, well, I guess it fit well enough, but it weighed a ton and it was a women's frame bike (not WSD, but the kind you can ride in a skirt and that has inefficient transfer of energi from back wheel to front) Trek just about had a fit when she saw what I planned to ride on at the Cinderella century. One LBS she took it to to get it prepped for the ride said "I give her an hour." So she took it to her favorite LBS, had slicks put on it, and off I went. Managed 42 miles in rain, hail and headwinds. Not so bad. And it was fun because I had a fun lady to ride with (Mel -- another TE gal). Then, when I felt I could afford to trade it in, I got a much better bike. So do not despair. Get your Mom involved with TE. We'll back you both up with plenty of encouragement.