Mine takes only live and isn't big enough to handle large rats so we have to just feed her a lot of mice. You could get someone to show you how to do a cervical dislocation and try pre-killed a time or two. That's usually a good stepping-stone between live and f/t.

If she's still taking the occasional f/t prey you could always play the waiting game, but I'd wait till after she lays to try that. Who knows, she may go back to her normal eating habits after laying anyway. They can be funny animals sometimes.