It seems Susan Holloway Scott is stuck on Charles II (aren't we all LOL) & her latest novel, The King's Favorite, is about his relationshp with Nell Gwyn (her last, Royal Harlot, was about Charles & Castlemaine, & her next will be about Charles & Louise de Keroualle, so keep yer eyes peeled).
Scott's novels are always 1st-person & always from the female POV (so we dunno what Charles was thinkin with all these mistresses alas). She takes Nelly from her humble beginnings in a whorehouse in Coal Yard Alley at age 11 (her mum & her sister Rose worked there in the capacity you're thinking, but Nelly allegedly was a mere serving wench) where she strikes up a lifelong friendship with John Wilmot, the notorious Earl of Rochester (who died of the pox AKA syphilis at age 35 & passed it on to his wife & son, who shortly followed; methinks he was the subject of that Johnny Depp flick The Libertine).
Nell is determined not to end up a raddled old gin-soaked whore like Mummy, & wheedles her way into her famous position of orange girl at the King's Theatre after a brief experience "in keeping" with a London draper. She became actor Charles Hart's protege & mistress, & soon had taken her place on the London stage as the first comedienne actress. Hart got a lil jealous when she racketed off to spend the summer at Epsom with Charles Buckhurst & dumped her, but by then Nell was well-established as a darling of the crowds.
Scott's opinion is that Nell did not have anywhere near as many lovers as Castlemaine, & that she was what we would term "serially monogamous". Certainly after Nell began sleeping with Charles, she's not linked to any other man in that way. She states Nell truly was his favorite because she alone had the ability to make him laugh & forget his woes, unlike "Carwell" with her whiny tears, Castlemaine with her colossal tantrums, & Catherine of Braganza with her long-suffering piety.
Nell was famous for pulling "pranks" to amuse the court, most often egged on by Rochester, Buckingham, & their ilks. One of the most famous was when she called to her elder son by the king, "Charles, come here, you little bastard!" in public, much to Charles IIs displeasure, & then innocently stated, well, he's no other title I can call him by, does he? Charles promptly rectified this deficit by creating the lad Earl of Burford & giving both his sons with Nell the last name of Beauclerk (a pun on Stuart, as a "beau clerc" would be a "steward" in French). Unfortunately the younger boy, James, was sent to school in Paris aged 7 & never returned, dying there of blood poisoning from a scrape on his leg he got while pulling some schoolboy prank, too afraid of the consequences to mention he might need medical attention until it was too late to save him. Charles Beauclerk did grow up to spawn 13 children of his own....imagine if any of Charles's bastard progeny had been legitimicized, the Stuart rule would never have ended!
The book ends shortly before Charles IIs death so as to have a happy ending, but the afterword gets one up to speed. Nell only survived Charles by a couple of years, ironically dying of the same thing he did, a series of strokes. Scott wonders if the whole damn court wasn't poxed at this point & if that was a contributing factor to so many of them dying so young. Nell never did get a title as Barbara & Louise did, the opposition to her humble birth enormous, but after he died it was discovered Charles had drawn up a patent to have her created Countess of Greenwich, & his last words to his brother James were alleged to be "Take care of Nelly", so perhaps Nell Gwyn, commoner, truly was his favorite, after all.