That would be a rather ironic shift in meaning; maids and maidens without their maidenheads.
Which is exactly why, given human nature, it’s a likely term for a prostitute. Compare “Get thee to a nunnery”: In Shakespeare’s day, “nunnery” was slang for a brothel. See also “upright fellow” or “legitimate businessman” for a member of a criminal organization.
Of course, you could use all of these suggestions together.
Joe: Mary is a senseo.
Bob: A what?
Joe: You know, a companion, a courtesan, a whoroid, a satisfier, a meretrix, an erotizan, a doxy, a star whore, a lady of the stars, a cyprian, a rocket rider…
Padawan.
What?
I’ve got it!
Client Server.
Starlot!
I came to this thread specifically to suggest “Licensed Companion”, but I got it from the “In Death” J.D. Robb series. Cool stuff…apparently, prostitution will be legal in 2059. 
Interstellar-distress-call girl
Whorp factor.
Coozemonaut!
cum-capsule?
planet of the gapes?
denizen of uranus? (okay, that’s a definite no)
transactor/tranactrix
a mete-whore?
release engineer?
a bacchan-alien?
Weirdly enough, in the series Ai no Kusabi, the Furniture are the people whose caste is too low to be a whore and end up being the bodyguards for them instead.
For the caste: Coitusian
For the individuals:
Copulatrix
Concubix
For boy-toys (male to male):
Urano (not from what you think [perhaps](Saturday, March 4 1230-130))
Ganymediator
I think succuba, for “she who lies beneath” is also usable, though it may mostly mean “mistress/kept woman.”
I could see changed meaning for maid, dear, jenny, nurse, secretary, help, queen…
*Sexgineer * if you’re being silly.
*Succu’ * if you’re being a bit punny.
http://catholic.archives.nd.edu/cgi-bin/lookit.pl?latin=succuba
"succuba
succurro : to run up under / aid, assist, help. "
I love it. If you do this, you should push it as far as you can. Find something that in the current day has absolutely no sex appeal and try to make it work. For example: kissinger. Which I also like because, if you strip away the cultural context it kind of works as a combination of kissing + messenger.
Yesterday I finally caught up with Heinlein’s “All You Zombies”, which I’d more or less known the plot of for years but never read. In it, “service station” doesn’t mean anything to do with pumping gas, and he makes reference to visiting a service station (as we use the term) and remarks that it doesn’t have a bed.
What makes sense within the world about which you are writing?
How exactly have prostitutes come to be a venerated caste?
What’s the cultural landscape and heritage? What languages are in use and where did they come from? Who is driving the slang?
Oh, I forgot “highly venerated.”
Um, I just made up “mamantai” for you. It’s altered from a Spanish word which translates as “sucker,” but no one has to know that.
Or something harking back to Hellenistic temple prostitutes, like “Sakerdess” as an adaptation of “sacerdos.”
"send in the FEMBOTS!!!