Here's a few things I noticed:
-try to get her going a little more. Her hind hoof should be stepping in her front hoof print in the trot aka 'tracking up'.
-relax in your arm in shoulders. The line from your elbow to her mouth should be unbroken and your arms should flow gently with her movement at the walk.
-rotate your hands up instead of sideways and keep them more up and in front of you. Your hands are getting close to the saddle, so you may want to shorten your reins as well. When you post, your hands should remain stable rather than going up and down with the rest of your body.
-your seat is quite nice, but you should tuck your tail bone/pelvis under you more during the sitting trot and canter.
-keep your toes parallel instead of sticking out.
-at some points, it looks like you could be using your outside rein to keep her straight and think of moving her shoulders with your legs instead of moving her head with your hands.
-for the canter transition, don't lean forward and give her the reins. Your reins should have the same contact they did at the trot and you should sit deep instead of leaning forward. It may help if you tilt your right seat bone forward and your left seat bone back for the right lead, visa versa for the left lead. When you canter, try not to perch onto your hands and let your arms move with the canter flow.
Hope this helps!
"The trouble with the world is that the stupid are certain and the intelligent are full of doubt"