I've only ever used frozen-thawed, but like nearly every BP owner on the planet, have experienced the eating dry spell.

Not much worries me more with the BP's than when they go off their food, even when it's expected around breeding season (with my small collection).

But when I am concerned over an eating habit, or lack of more accurately, I will introduce multis just to try and reignite the feeding instinct.

Multis are native to Africa and haven't failed me yet. I've also read gerbils are like candy to a baby with BP's but have never had to get to that point.

So what may be worth a consideration is just getting her used to frozen-thawed, whether that be something like gerbils or multis, something she'll find hard to resist, and once established on frozen-thawed, try to introduce normal rats when you feel it is the right time.

Hope this helps.