I generally agree on drilling clear hips to death, keeping perfect shape, getting higher and higher, but they also have one of the strongest timing/clicking/figuring it out functions. If after 2yrs there doesn’t seem to be progress, I wonder if another way to explain the timing would help. If there is a way for her visualize it as a back extension roll with the same pop open, shooting toes in same direction she would to get a handstand out of a back extension roll, it might just click. Have her watch videos of the clear hip and see how it is a backward roll around the bar, and popping open, shooting toes, opening shoulders, whatever phrase she uses to get her back extension roll from a backward roll to push-up, into a handstand. Her body can do it, she just needs her brain to connect the pieces.