Well, I am not a jumper but this is what I see:
I see daylight behind your knee, so I know that you have so much calf on that your knee is coming off. Rather than calf on, get your heel down. That will discourage you from clamping onto her side (and this may be one reason that she is not offering any bascule over that jump.) Bascule is the gently ark of the horse's body that comes when they really use their hind end and abdominal muscles to lift the back and front end. Some horse's have natural bascule and others don't. I would guess that maybe your horse is not naturally built to have good bascule. Her not being able to lift her knee up can also be markedly affected by her conformation.
However, if she has plenty of room up front to use her head and neck as a counter weight in the jumping process, she will do better. Is that a hackamore you are using. ? Got to give a radical release , I think.
I don't see that you pony is getting hurt or anything, but I dont' think I see a lot of confidence there.
What will happen if you hit the pole with her feet? The barrel will fall over, no?
Will she take a mongo spook at that?