My girlfriend thinks I said she was desperate, but i didn't say that.?

Yeah but the way you said it sounded like you were calling her desperate. And a lot of people are not content with being single. I'm not content with being content with being. That's nothing to be ashamed of but that doesn't necessarily make people desperate. Anyway you seem like a really like nice and I can tell that you did not intent to offend her. You were just pointing something out. But yes apologize to her it just a simple mistake no big deal. It's not like call her easy or something.