is it legal to defend yourself if attacked by an adult female?

Settle down, hero. You sound like you're itching to beat up your girlfriend's mother. You won't impress your girlfriend if you do so find another way to get in her pants.

As other have said, it depends on the state you shoot the person in. If you are in one of those states run by liberal gun control bigots, you are going to jail. If you are lucky enough to be in a free state and you were in a situation where any rational person would thing their life was in danger, or that great bodily harm was about to be inflicted upon them, yes you can legally use deadly force. Now it is a black person you shoot you may even see jail time for a completely legal shooting as George Zimmerman found out. The police found that it was a justifiable homicide, and didn't arrest him, the DA found that it was a justifiable shoot and didn't have him arrested. Then the lame stream media got into it with their lies and the State DA had Zimmerman arrested, because 0bama told her to because the scumbag thug was black.

If you're in her house you have to leave before you resort to any physical force. If you're out in public you're allowed to use an amount of force reasonably necessary to defend yourself - but no more.

Yes, but i would recommend you don't beat her to a pulp. Restrain her, grab her to get off and push her aside don't beat on her because you're stronger than her. Even if she she is wild. But yes you can defend yourself.

To defend YOURSELF, yes. To defend your girlfriend, no.

And, it's only legal to defend yourself if you are "fearful of imminent bodily harm"

Yes. Females are not exempt. Don't let the conservatives or feminists convince you otherwise.