You might contact the Mad Cows Tri team as well as get on the DBC email list. Post that you are looking for a used bike.

Other clubs in town might have email lists also.

Just don't buy her a tri-specific bike at this point. They aren't really comfortable for general road riding such as centuries. At this point in her budding career, she may decide againt tri's and go for centuries or even brevets. A road bike will be much more all purpose, but if she really gets gung-ho into tri's she'll want both.