Disclaimer: I bought the paperback edition of this book when it was first released in 1981. Although I have had some communication with the author, it was many many years ago and had nothing to do with this book or a review thereof.
This is actually a pretty good book, different from most historical romances of the 1980s. And though it's been years since I've read it, certain details stick in my head.
To begin with, Portrait in Passion is very well written. Even now, opening the book to a random page, I'm immediately pulled into the scene, into the action, into the setting, into the characters. Good writing is enormously important in terms of how well the writer is able to convey the story, regardless whether the story itself is good or bad. Osborne's writing is more than sufficient to the task.
She has also, however, constructed an interesting and believable story. The heroine Kate Callahan is beggared by the death of her wealthy but profligate father. Forced to make her way in a time and world that is not kind to desperate women, she leaves Victorian New York for the Bohemian artistic life in 1870s Paris. She is married to an artist who, I think, eventually goes insane, but she is pursued by another man, too. After these adventures, she leaves Paris -- I think the husband dies -- and returns to New York, where she becomes a newspaper reporter, attending all the high society social events and writing up the accounts of the menus served for dinner, the quality of the orchestras that played for the dancing, which wealthy matron wore which jewels and which young heiress was seen dancing with which handsome fortune hunter.
And it's a scene in which Kate converses with one of those aspiring society hostesses that Osborne writes one of the most unintentionally funny lines I've ever read in a historical romance, particularly one set in 1870s New York City.
...Kate smothered another sigh. In all likelihood she was indeed Mrs. Pepperalt's most important guest; Kate's printed opinions would determine Mrs. Pepperalt's social future. Pasting a smile upon her lips, Kate resigned herself to the cloud of gushing green silk, tactfully fending off Mrs. Pepperalt's attempts to elicit advance information as to the direction of Kate's column.
"I hope you enjoy the decorations, Miss Callahan. I had orchids flown in from Brazil especially for this evening!"...
"Interesting," Kate murmured.***
Although this had me rolling with laughter, it doesn't happen until page 453 out of 487, so it wasn't enough to ruin what was actually a very enjoyable book with a very satisfying happy-but-not-quite-traditional ending. Highly recommended.
*** I would learn some years later from a friend of Osborne's that she was absolutely mortified that this error had made it into print. She had originally set the story much later, well into the 20th century when such an extravagance would have been possible, but her editor demanded that the time period be moved back. This was one detail from the original that escaped detection and revision.