I was wondering if I didn't see a little bit of fourbeat canter in the first video. She canters a little like a gaited horse . Anyway, what I mean is that the canter lacked a bit in impulsion. YOu sit the canter very well.
In the second video I couln't quite see the haunches in. To be honest, I don't see a bend in the mare at all.
I also saw that toes down in the last video. I get the feeling that you are not letting your energy down all the way into your lower leg and foot. You kind of ride really lightly on your thigh and seat, which is great (fantastic sitting trot), but your lower leg reads as ineffective and this may have something to do with why you don't have as much bend as is needed.
Your hands are sympathetic and steady, head up nicely and upright upperbody.