Learn how to read the signs, and don't call them anything vulgar within that person's earshot.

[There's a rustle of cloth, as though she shrugs before remembering that she can only be heard, not seen.]

I get the impression that there isn't a formal guide to what to call non-Blood. My old etiquette tutor would turn over in her grave to hear me suggest it, but why not ask a non-Blood woman how she prefers to be addressed?