This has also happened to me... come to think of it, more than once. I remember kicking myself (mentally) for not going right up to her and introducing myself, to find out her name and hours, but the girls who've served me always seem to ensure my direct exit.
On the occasions when I have been so bold, explaining that I would like everybody to recognize me, my requests have been granted without issue. However, this has only been in AMPs where the other girls are not of dramatically higher quality.