The reason she's hitting that knee has to do with her avoiding letting the right hip rotate to roughly 45-degrees before the shoulders do. If she would let that right hip go forward some as she goes into release, she'll get good brush contact, she won't whack her the inside of her front knee, and her poster will be better (spine closer to perpendicular with ground on release.
I believe the "knee-kick" drill without a ball will help her a lot. Maybe Rick Pauly could step forward and describe that here.
I wish I have a better video showing how she actually sticks her bottom out in order to avoid the "brush."