Saddle is to small
Stirrups need to go down at least 2 holes.
-That will help your leg come down long and under you.
Riding in two point because she is frisky, I understand but you are making yourself venerable by being forward, get your butt down, if she is that frisky don't canter her, go back to walk and trot, plenty of transitions and turns before going back to cantering.
Now it's difficult to tell n those pics, but you look tense to me, like you are not breathing, and waiting for her to explode with you. SO hard to tell that from stills though, but it is the impression I get. If this is the case, the transitions change of pace and direction, lots of control exercises will help both of you relax.
I have an Arab who looks much like her way of going, you can't wear them out, or 'force' them down, the only way to get control is to get them thinking, keep changing it up so they can't anticipate. The down side is I nearly got giddy with the old girl, I've never ridden so many circles, voltes and serpentines, and OH JOY, I have it all to do again with her daughter