If she is of average height for a woman (around 5'3"), a 49 for the men's version is going to be too tall. A 46 cm bike is better for an average sized woman and something much smaller is needed if she is shorter than that. That's going to be the problem with older bikes also. Many of them were made in sizes which just don't fit women that well.

However Jamis does make a women's line which is better proportioned for women. The Ventura Sport Femme' would be a good inexpensive choice. If she doesn't want to go with a dropped bar road bike, abstractform20, look at the Specialized Vita or any of the Trek WSD bikes. Be prepared to spend just a bit more than $400, however.