Lady Sally McGee is the wife of Mike Callahan. Before its closing she ran Lady Sally's Place, a brothel in New York City. It was an unusual brothel in that it respected the rights and wishes of both "artists" and "clients" equally (and carefully). Those who couldn't or wouldn't abide by the house rules of courtesy would get an "invitation to the world"--usually via Priscilla, her extremely buff but nevertheless extremely sexy bouncer. Her House was yet another iconic fixture of author Spider Robinson's axiom, "Shared joy is increased, shared sorrow is lessened." The McGee books are enjoyable both as stand-alones and as part of the larger Callahan's series.
Spoiler Alert: In actual fact, Lady Sally (married to the same Michael Callahan who ran a highly successful bar on Long Island for so many years) is a Time Traveler, here in the world on a specific mission. The details are a bit fuzzy from her far-time perspective, but in essence she's here to prevent WW III--and mankind's self-annihilation in an "almost inevitable" nuclear holocaust. All future-history theory predicts this should've happened--yet it didn't--so somehow or other she and/or Michael must have found a way to prevent it. Hence, their presence.
She goes about achieving her goal through "informal diplomacy" at her very large and extravagant brothel located not far from the United Nations. Through these quiet behind-the-scenes negotiations, she has been able--for example--to keep the United States propping up the USSR financially for some years, though this is only "buying time." Her sex workers (male and female) are almost invariably highly intelligent and talented, usually multilingual, and are frequently given state-of-the-art training courses in "The Art" to help improve their already stellar performances. Through this means she has made (um) intimate acquaintance with some high-ranking contacts in both the KGB and the DIA (Defense Intelligence Agency--better funded and quieter than the CIA!), which will come in handy in the course of time. End spoiler alert.
There are only two novels in the series that take place at Lady Sally's establishment: Callahan's Lady and its sequel, Lady Slings the Booze (possibly the best punning title ever!). Only the second deals directly with Lady Sally's here-and-now mission, though she does reveal herself to two of her artists by the end of the first. Each novel is narrated in the first person by someone who more or less accidentally comes to work for her. Each follows the typical Spider Robinson formula of a series of smaller vignettes leading up to a major storyline.
Book One follows the exploits of Maureen (House name: Sherry--don't ask), a "common" street hooker whom Lady Sally stumbles upon in the course of her night and rescues from a brutal pimp trying to knife her to death. Given her many talents, Lady Sally makes short work of him and he scampers away with his tail between his legs. She then takes the girl to her House to tend to her wounds (she has a very kinky, but genuine, doctor on staff) and give her time to rest and recuperate. As Maureen pieces together the clues to her current location, she becomes convinced she's been shanghaied by a woman possibly more dangerous than her pimp (a very wrong conclusion on her part, in terms of Sally's intentions), and attempts an escape--but her injuries are far too sever and she makes a botch of it. Lady Sally forthrightly informs her that she has no intention of asking (or telling) Maureen to work for her--ever. Partly because she's obviously still a minor, mostly because she not so secretly holds her very lifestyle, and her clients, in contempt--an attitude Lady Sally is unwilling to work with, based on prior bad experiences.
While Maureen recovers, she gradually learns the whole truth about Lady Sally's, whose culture is much different than anything she'd expected. For example, Lady Sally actually has a rigorous screening process, and a large number of House rules designed to protect artists and clients alike. Partly to enforce these rules, partly against any emergency (like cardiac arrest), she has an unadvertised "Snoop Room" where her daughter Mary monitors constantly for any signs of trouble. She lives, exudes, and expects High Standards--but she also wants everyone in her House to have fun at least the majority of the time. (In fact, the coed parties in her main Parlor (dress code strictly enforced!) are notoriously so enjoyable--with raucous barrelhouse music, smoke ring competitions, and frequent wordgames) that sometimes the clients forget to go upstairs!
By the end of this novel, Maureen has become an employee, despite Lady Sally's initial reservations--and is revealed to have some unsuspected depths (a former army brat, she speaks fluent Japanese and is an accomplished martial artist) who drifted into her current life as the result of an early emotional trauma--the true cause of her "contempt". Spoiler alert: She was also briefly mentored by one of the greatest con men on the Eastern Coast, "the Professor", who puts in an appearance by the end, and proves pivotal to the major plot. She helps Sally and Mary dispatch Big Travis when he finds his way to the house (high, of course) spoiling for a fight. She helps a neuroscientist who implanted himself with some, uh, "extra" in a sensitive portion of his anatomy--to his lasting dismay as his urges become all but unstoppable--find a place at Lady Sally's, where he can at least blow off enough steam to still function. She helps Sally quelch the designs of an angry blonde with a sinister mind-control device who has chosen this House to beta-test it at (plenty of ready victims in one place, and all). And she helps devise the downfall of a criminal goon so tough, he goes it alone against the Mob as a competitor--and they look the other way!
Book Two follows a different protagonist--Joe Quigley ("House" name: Ken Taggart), a private detective who has been hired by a Significant Figure in local politics (just don't ask him how he's doing!) who has been embarrassed to look into some suspcious activities at Lady Sally's house; apparently there is a prankster loose with a penchant for mean and even violent practical jokes but whom no one can seem to catch in the act. (This despite the presence of the Snoop Room, and all of Lady Sally's other precautions.) Sally has taken to calling him "the little man who wasn't there." After some initial misunderstandings with the Lady (like Maureen before him, he has a lot to unlearn about the trade--at least as practiced at Lady Sally's), he agrees to take the case--and is swiftly laid out with his own blackjack. (Not only is this prankster mean and violent, with a sick sense of humor, but his escapades are escalating to increasingly dangerous and ultimately deadly levels. Spoiler alert: The least appalling thing about this villain is that he has invented a device which can bend time itsel to his will. Ultimately it will take some pretty heavy future-tech to put him down for the count. 'Arguably the greatest villain-you-love-to-hate in the entire Robinson corpus.)
From there, the novel segues into the Lady Sally as Time Traveler plotline, and her specific purpose in being here-now. (Joe, an intuitive genius "with incredibly bad luck"--or perhaps better stated, a penchant for leaving holes in his theories--has deduced much of the truth already and confronts Sally, who feels obliged to him and so confides the truth. Also, given his almost paranormal intuitive gift, she sees him as an amazingly valuable potential recruit. And, indeed, from his now-time perspective he's able to fill in the gaps that Lady Sally and Mike alike have both missed--the true danger is coming from "peace terrorists" who mean to threaten the world into disarmament and have been mining the sewer systems of major population centers--with nukes--for some time. In cooperating to quash this mutual threat, the two major world powers are forced to work together and truly are "scared straight" by the tightrope they've walked--but first, Lady Sally's handpicked crew have to bring them credible proof--and, ideally, one of the bad guys for interrogation. This they manage, though not without some of the usual hiccups on the way.
Like Mike, Sally is a full-fledged Time Traveler (the extent of Mary's ability in this regard is never made clear, though she's clearly in on their secret; she may in fact be "native born" and lack the Harmonian gift, though not the genius); also, 'Lady Sally has demonstrated the ability to Translate, but required a disguised "portal" to do so. It is never specified if this is a limitation of hers or merely an incident that was retconned when Translation was described by Mary.
(The portal appears to be merely a device-of-convenience so that Sally can go to any other this-Earth point from her House instantaneously, without having to "go home" first. [Theoretically, she and Mike can access any space-time that they don't already occupy, and can even time this down to the micro-second so their absences aren't missed. However, in at least one vignette she actually does go home to Harmony through the portal, taking a passenger with.] The specifics of the Callahans' time travel aren't directly discussed in the books; the hints seem to imply it's an innate psychic ability, but Sally does mention "time-travel gear" at one point. This may actually be an implant that the Harmonians have implanted in their brains, responsive to specific synaptic patterns. Hint-hint, Spider?)
All in all, the only downside of the Lady Sally books is that there were only two of them before Lady Sally fulfilled her purpose and left to do other things. Since some of fandom found them even more enjoyable than the Callahan's Crosstime Saloon tales, that's a bit of a sad break. (Of course, "earlier" stories can always be retconned in--and the challenge of operating in a Seventies-Eighties world with no Internet could even add interest, though the Callahan's have proven proficient in getting around such hurdles--with the help of the historic (though presumably long-dead) Nikola Tesla.) A textbook model of how houses of prostitution should be run, in anything like an ideal world--and all done with a sense of humor, to boot. A fine addition to a superlative series.