If you have access to live mice, then feed her that. No use in her starving herself or not eating consistently on f/t.. Feed her what she wants until she gets some size 3-400g, and THEN try to switch her. Once she gets happy and confident about eating, you can try to slowly switch her.

Also, feeding her a live mouse, then offering up a very warm, thawed mouse afterwards while she's still in feed mode is helpful.

But.. feed her live for now. It's what she wants.