Well, before we were talking about "defense of property". Now you are talking about self-defense, and that right exists anywhere -- but the facts must support it. The law recognizes a greater right to use lethal force based on all the facts and physical characteristics -- so the judgment call will be easier when a woman is defending against a man, and I think the your conclusion is right in your hypo.
But in the case we were talking about, 2 men had guns, and surprised the assailant -- not the other way around. I find it implausible that they didn't have a way to stop the burglar without using deadly force -- but again that's what trials are for.