The next time you try F/T, warm up the head even more with a hair dryer for a bit (the rat, not her!) and then hold it in front of her on tongs and "tremble" it a little. Don't bonk her with it or run it around the cage. It also might help to hold the rat by the back with the tongs, rather than dangling by the tail. See if she'll strike and wrap that, and if she does give the rat a couple little tugs to make it seen alive and resisting her. Obviously don't pull hard enough to scare her or take it out of her coil.