Can you post a video of her shaking her head ? Just to rule out a possible neurological disorder.
It would be good to pick her up every day for about 10 minutes at first. Pick her up, supporting her body, and be very calm even if she flails. You may need light gardening gloves and long sleeves if she scratches + struggles. Then just hold her gently + firmly to your chest for the whole time. She should get used to that after a couple of weeks. Then you can try it along with sitting down in a dragon safe small room, [ like a bathroom ] letting her sit in your lap. If she wants to stay there, that's fine, or she may want to roam a little bit. Be sure there are no spaces for her to squeeze under or small foreign objects [ coins, rubber bands, etc ] that she might swallow.....that happens often with beardies.
She should get used to handling like that in a few weeks and then can do so for longer periods of time.