I've never had to heat up feeders for my boas and they all eat f/t or f/k. I just thaw at room temp and dangle them in their face with some tongs and they all eat like there's no tomorrow. Just give her some time and be paitient it will happen, don't give her anymore live and only offer a f/t or f/k until she eats. Even skipping a few feedings won't hurt her at all, a boas metabolism is a lot slower tha a bp's. Boas don't eat on a schedule or as often in the wild as they do in captivity and fair just fine without food for even months at a time with no I'll effects as long as they always have fresh water. Good luck and with time, patience and persistence she will be off of live food!