Another fishy thing about this part of the story is that Dana (of which I assume "Dayna" is a variant) has traditionally been a name given to both males and females. So even if the couple took Ms Morales to be male, there was no reason for them to express surprise on hearing her name.
I'd probably have commented and made a little joke about hearing the name wrong if I heard a male's name and a female ended up serving us. Dana took offense to it because she assumed they were joking about her looks (my understanding, could be mistakne) by being "surprised" by her feminine name.
Well, now I won't ever again since you can't be sure joking and banter with your server won't get you internet flamed.