No, she did know what you said. She was just commenting on the use of gay in general, and explaining why she called you out on it. I thought that was pretty straight forward.
The point also stands to you using the word niggers. I am guessing, seeing you are an 18 year old australian kid that you aren't like the people who have started reclaiming the word, and don't have any cultural connection to it. You shouldn't be using that word anyway, it makes you look like an idiot. If you came in here and said that, people might not have gotten so PC about it (because we are all mostly privileged white people), but you wouldn't be taken seriously.