In my Week 49 Illuminatus reading group blog post, I reported on Jesse Walker's article on the American anarchist Mary Frohman , which mentioned the possibility that Frohman had inspired the Mama Sutra character in Illuminatus! Jesse wrote, "Mary, for whatever it's worth, believed she was the basis for the book's fortune-telling character Mama Sutra. Shea, alas, isn't alive to confirm or deny that, and Wilson tells me he doesn't remember Mary; Fish doubts that the story is true. Oh, well." (The passage refers to famous science fiction "filker" Leslie Fish, her lover for many years.
I wrote to Neil Rest, the real life inspiration for Simon Moon, to ask if he had any information, and he said he did not. But Neil wrote to Fish, who responded, "Yes, Mary was part of the inspiration for Mama Sutra, but not all of it. After working at Playboy for years, Shea and Wilson knew how to skate around libel charges by creating composite characters. As Bob Wilson used to quip, 'Steal from one writer and it's plagiarism; steal from two or more and it's research.' I believe enough elements of Arlen, me, and even Janet Miller were added into Mama Sutra to keep her from being a sue-able (not that Mary ever would, but survival habits are hard to break) depiction of Mary."
UPDATE: Jesse Walker Tweets a link to this blog post and says, "This isn't what Fish told me 10 years ago. But it may well be true." Well, there's no way to know for sure. The "based on her but also a composite" would follow the Simon Moon pattern.