Do not give it to the other snake, she will just get stressed and it will put her further back into her shell. She needs to be left alone completely.

How big is the rat? If it's any bigger than 50-60g, then you will want to take it back. Male Balls don't need anything bigger than 2 adult mice a week or a weaned rat, or they will fast(which is likely what he's doing). If you've been feeding him medium rats or larger, then he's probably just fasting so his body can catch up.