Everyone is on-target.
For the brush resistance, have her wear a loose fitting t-shirt. Have her concentrate on moving her upper body to the arm (not arm to the upper body). She should feel her arm brush the t-shirt.
She needs to do this drill about a million times:
Loose shirt! DD was learning the curve a few years ago and threw a great one. I yelled do that every time. She said that would hurt, my finger got hung in my shirt.