Multi-part question

It could be that. She's been stagnant all winter, and isn't being ridden regularly now. The woman who owns her said Jesse has pulled the same stunt with her though, and she's probably a more competent rider than I am.

I will definitely look into a tack fitter, and it may just be an issue that will resolve itself with time and regular riding. The daughter of the owner said Jesse's trainer would get beautiful canters out of her, and she was in regular training for at least 30 days.