My physical therapist streched me to the point of pain, but it was controlled and healthy pain: muscles and tendons being streched by a medical professional. I would be highly cautious about being pushed to that point in a non-individual setting, especially if she's new to that coursework.
My Kajukenbo instructor gives us some stretches like that, but it's 1-on-1, and they are to be slowly increased over time with good form, not forced into position.