My suggestions in order of priority:

1.) To create a more natural looking animation, I personally would suggest reducing the amount of spins and making the jump a bit less floaty, as it currently looks as if she's jumping in a low-gravity environment.

2.) She looks as if she's preparing to do a normal jump upwards, but then she suddenly starts spinning. In order to actually spin in mid-air, you have to twist your body/vertebrae before jumping, and then "unwind" during the jump. If you add some twisting before the jump then it may look a bit more natural.

3.) The momentum of suddenly stopping that extremely fast spin would be affecting her boobs as much as gravity does, so they should be swaying to her left upon landing and then bouncing back.