The secret behind Barbara Cartland's prolificy was the fact that SHE DIDN'T WRITE THE BOOKS.
She had a secretary who wrote the books. Barbara only told the stories.
So, if you are a millionaire, you get yourself a secretary and an editor, who will do the boring job of writing, and you just sit on your behind, eat chocolate and fondle your lapdog.
Now, considering this, it is not fair that she is in the Guinness book of record as the most prolific author. She is a storyteller, not a writer!
But - rest in peace... She would have done the boring job too if she had needed to...
Writing isn't boring. It's just story telling. What is boring is editing - correcting the language, grammar and finding a better way of saying a thing. Killing your darlings, stripping away all the unnecessary words (2/3 of them...)... editing. It would be so nice if there was some editor, secretary or ghost writer who could do that for me. I would love to be "just" a storyteller.