According to the penal code in the USA, does self-defense (for example, shooting after a rape) require that the response be in direct proportion to the threat itself, or as the person who shoots reasonably perceives it?

In other words, if the person who did the shooting thought she was about to be raped, can she kill her attacker? I ask this, because there must not be reasonable doubt, so, proof, but I can’t grasp what it can be here. Now, there’s to consider that this is an extremely generalized example, but I don’t think it’s a bad thing. There are only so many ways to answer this question. Anyway, if you don’t understand, ask away, and I’ll answer as best I can.