Katie, You've gotten lots of input and things to consider/try. Another
idea that I would think about is lunging her (if she knows
how) without tack and then with tack. You can observe whether she seems at
all uncomfortable beginning with transition to canter. The without
tack and then with tack may tell you about some discomfort she's
experiencing with the saddle on. You can compare her attitude and movement
'without tack and with' on the lunge, to with tack and rider.
