I hate to be the one to say this. But it would be very difficult for a woman to keep up in the Tour de France. If you compare average speeds at women's races to men's there is a significant difference. Few women could maintain a 50 kph for a 50k time trial.

In the Worlds Elite Women's TT: ave speed of winner 46 kmh (23k)
Mens: 50 kph. (40K)

I would love to see women in the Tour de France but in reality men and women are not built the same.

Angricow: I hope you can train and be the first woman in the TdF. I too have fantasies about riding in the Tour....