Fainting after sex? Good, bad or is it normal!?

Well today we were making love my girl and I and we wer doing it in the doggie style and after I came she told me to eat her out so I did and I stimulated her by her c l I t and through the G spot after she orgasmed she told me she felt weak and a few secs later she freaked out cuz she had lost her sight she told me she would see black and later on she dropped and fainted but before she came to she made a scene like a "demonic possetion scene" and after dat she came back and she told me she didn't remembered anything so I just wanted to know if this is normal. Thank you for your time and answers.