I"d just recommend feeding the normal mouse to the BP. As for your corn snake, if she's used to eating F/T, I'd just humanely kill fred, and give him to the corn. Either that or try feeding her live. Shouldn't make much of a difference in her eating habits. Only risk is that she won't go back to F/T. I'd wait and see if the female mouse gives birth. If she does, you'll have some free mice to feed to your BP. Otherwise, you just have a mouse to feed. A link to an image is below.

http://oslovet.veths.no/teaching/mou...ederive/1a.jpg