Is her seat slide all the way forward or back? Where is her knee position relative to the pedal and BB?

I would have her level out the seat first, then slide her seat such that each push of the pedal will also push help the pelvic back and not just vertical. After that is set, then adjust the tilt downward if needed but not to the point where she is constantly sliding forward. Now check her reach of the handlebar. If the seat was slid back, she might be over reaching and putting more pressure in the sensitive area of the seat. If that is the case, then change to a shorter stem.

Note: If her seat us already adjusted properly, then she maybe over reaching and leaning foward which might put more pressure up front in the tender area.