Yep, exactly, hang drills. The body position that the flyer is in in the hang drill is the exact position they need to be in in the load in for the basket. For the basket, the flyer should complete a similar motion to a simple load in up to prep (elevator). They jump to load in in the "hang drill" body position and as the bases dip the flyer pushes off from the shoulders, locking their arms out. If they do this in a basket and their weight is over towards their feet and not leaning backwards, when the bases toss her she will go straight upwards, and will not need someone at her butt.
Practice simple straight rides at first, and also work on getting the flyer to the load in position and pausing before the bases toss. This way you can make sure she is in the correct position and she only has to focus on the pushing off from the shoulders and not the load in at the same time - as she becomes more confident, connect the load in straight to the toss. Hope that helps!