Is it creepy to read a coworker's name tag to find out there name?

One time when I was a cook I asked one of the servers, who had only been there about a week or so, something about her order. I called her by her name and she was like, "how do you know my name, that's creepy" and I said, "because of your name tag" she just said ok and that was it. But I still felt creepy, like I don't want to make anyone feel weird. I didn't think it was a big deal to read her name tag to find out her name.