Dorothy Phoebe Ansle (1890-1983), who wrote under the pen names Hebe Elsna, Laura Conway, Lyndon Snow, and Vicky Lancaster, published some 200+ books between 1928 and 1982. See the full title list: https://www.fantasticfiction.com/e/hebe-elsna/
I first came across this author when I read a book dedication in Jean Plaidy's Goddess of the Green Room:
For William’s and Dorothy’s Great-Granddaughter,
with admiration for her work
gratitude for her friendship
and love for herself
I managed to find a few of her books, but so far have not moved them up on my TBR list. There's not much information on this author available--not even a Wikipedia page, even though she was apparently a great-granddaughter of England's King William IV (with his mistress, Dorothy Jordan).
Here are a few of the personas she fictionalized:
Queen Elizabeth I, in The Red-Headed Bastard
Catherine Thomson Hogarth, in Unwanted Wife, in Defense of Mrs. Charles Dickens
Katherine Howard, in The Wise Virgin
Catherine of Braganza (self titled) - this one appears to be non-fiction
Charles II, Catherine of Braganza, Lady Castlemaine, Duke of Monmouth, in The King's Bastard
Frances Stuart, in Lady on the Coin
George IV and Mrs. Fitzherbert, in Sing for Your Supper
There's quite a bit of info on this website, although no mention of her connection to royalty: https://rmsghistoryextra.wordpress.com/tag/keogh/
Feel free to add to this if you have additional info on this author!
THE WISE VIRGIN
Jocelyn, the heroine of this tale of Tudor times, attracts the attention of Henry VIII. Her predicament is understandable--to marry the bluebeard King is to risk death by the hangman's axe, but to reject a king is to court the same fate.
It demands all of Jocelyn's wit and tact to evade the king's lecherous and unwelcome advances. But eventually she succeeds and is able to marry for own true love, while silly, pretty, flighty Katherine Howard takes her place at the King's side.
THE DOOR BETWEEN
This story explores the strange world of Guy and Mara Rankin, as seen through the eyes of Julie Shannon who loved them both.
Always there was the sense of uncanny, the eerie, about the glamorous pair, descended from Mary Stuart and Henry Darnley, which fact they disregarded until on a visit to Edinburgh the past caught up with them and they were forced to realize that a strange fate linked them to the city where their ancestors had lived and loved and suffered.
Exciting in its most fear-filled moments for them; but for Julie, normal and even a little commonplace, they were doomed creatures with a tragic fate.
SING FOR YOUR SUPPER
The story centres around the household of Mrs. Fitzherbert, the morganatic wife of George IV, before and after they finally parted.
Mrs. Fitzherbert was virtuous, loving and serene, yet there was a mystery about her and the two pretty girls who lived with her and were regarded as her adopted daughters. This was sensed by many of their friends, including Melita, the young singer, a distant family connection, who was a frequent visitor at Brighton and the London residence.
Melita, who sang as effortlessly as a bird, and did indeed often literally sing for her supper at the houses of the great, was an onlooker at the brilliant Regency pageant. She was the friend of both Minney Seymour and the rather mysterious Marianne, and was regarded by Mrs. Fitzherbert with affection. As a 'green girl' she was hopelessly in love with George FitzClarence, eldest son of the Duke of Clarence and his mistress, the enchanting Dorothy Jordan; but George loved the flirtatious Minney, and destiny had other plans for Melita.
THE KING'S BASTARD
Although he was declared by Charles II to be illegitimate, the handsome young man known first as Mr. James Croft and then as the Duke of Monmouth was believed by many in England to have been born in wedlock, his mother being Lucy Walter, Charles's early love. The romantic legend was that there had been a secret marriage which Charles refused to acknowledge, because Lucy was not only of no great rank, but also shamelessly unfaithful to him.
Whether or not this was the truth, it was certain that Charles loved his son and that 'Jemmie' when young asked for nothing more, and would have preferred a life of adventure to that of a prince.
In this novel is told the story of his early life before his love for his royal father was poisoned. Honours were showered on him by the King and he was a favorite both with Catherine of Braganza and Barbara, Lady Castlemaine. The association between the King's wife and the King's mistress was more unusual than generally supposed; there was a singular sympathy between these two women who both loved children and young people.