There's no double standard in this situation shadix.

You were offended by her but you didn't express it. No one said you couldn't, and she had zero way to know that you were actually offended. Because you said nothing.

Therefore, her speaking up when you offended her? Is not an example of women vs men. She chose to speak up. You didn't. You have no way to know if she meant it to be offensive or not - after all, you said something offensive and didn't know that as you hadnt meant it that way.

I am not biased towards your friend. She spoke up, you didn't. She even explained that it isn't the intent that mattered but the impact - she explained herself! You didn't. You didn't say a single word. She is not holding you to a different standard than she holds herself.