Oh. It seems like this person, Brienne of Tarth, has heard of her. Daenerys is noticeably startled, she wasn't expecting to be knelt to here. It didn't seem like a place where her status meant anything, at least the other people who she barged into didn't seem to think so.

"Tarth? That is not far from the place of my birth. You may rise Brienne of Tarth."

Dany may be a Dragon but she is still kind, she would not beheard Brienne for not recognizing her status.