Are you feeding in the enclosure? If so, you might want to try offering her the dead rat when she's in a hide. I find this is, by far, the best way for me to feed my guy. I'll drag the VERY warm rat across the hole of his hide a couple times, wait until I see his head poking out to know he's got the scent, and then drag it across again. He'll usually hit it the instant he sees something to grab onto.
When I was taking him out of his hides, I had to do a big elaborate rat dance, and then half the time he seemed scared of the rat. This way, I think it's more a "natural" hunt, as BPs tend to ambush rodents from inside a burrow in the wild.
If that doesn't work, try putting the rat in there and leaving the two of them alone for a couple hours. If it's still in there after like 3-4 hours, it's probably safe to take it out.
Make sure your rat is the right temp, that seems to really be the key to making F/T work in the beginning.
There are a couple more things you can try if these don't work, but really... DON'T STRESS! She'll eat when she's hungry.