The key is body tension. She needs to squeeze every muscle in her body super tight as she casts and goes around the bar. She can practice lying on the ground and being super tight. Toes pointed, feet squeezed together, legs straight and squeezed together, core tight etc.
She needs a nice big casts, with a super tight body and to look at the bar and squeeze her arms tight.
It often does take months to perfect gymnastics skills, sometimes even years. Its not easy, they need to remember to use every muscle in their body at the same time, which is super tricky for little ones. She is doing a great job.