I can't tell a lot from the video, but I'd look at your bases too. They're very far apart, and stay apart the entire stunt. The closest base is also leaning back to watch rather than stepping under. I think one of them is pulling the feet out by backing up, though it's hard to tell. Your flyer also needs to keep her feet together and arms tight. She's letting them flail, which isn't helping her at all. Make sure she goes up before twisting. Which grip are you teaching? It looks like a free release, but can be pretty hard for a non experienced group. Can you try a different grip (ruby slipper, half/half up) to give them the feel of twisting?
