Thanks for the reply Dr Cupcake.
It's a bit more mental than physical for her. She has good mobility and a smooth pedal stroke. It's mainly a fear of getting into the tuck. I have her practicing in a parking lot for short bouts and we made some adjustments on her fit that hopefully give her a greater sense of stability.
She does have a trainer and is riding in aero on those sessions.
Physical Therapist/Endurance Coach http://www.cadencept.net