Rok, I've got three books by and about "Nica". "Three Wishes" is the only one worth the freight. From a story book point of view, her life was far more interesting before she became "The Jazz Baroness".
The rumors that she was intimate with "black" jazz musicians constantly swirled around her; especially after Bird died in her apartment, and she never attempted to stop any of them; with so many musician friends, it would have been pointless.
In regard to her intimacies, including with Bird, no one has evidence of "any". Everyone who knew, including Bird, said their relationship was purely platonic. The alleged musicians, beside Monk of course, said they wished the rumors were true.
Stop and think about it, she was a 42 year old Baroness with 5 kids when Bird died in her apartment. While it's not uncommon for people of different races to become intimate, "Class" is another matter. Once people get past their animalistic youth, they take a great deal more consideration into "intimacies". A 42 year old Baroness would have instilled requirements in regard to someone she chose to become intimate with. It's my opinion, and I stress that fact without one iota of evidence, that none of the musicians, black or white met her instilled requirements for intimacy.
Musicians put it differently, they said that after having 5 kids, she wasn't interested in such things. Now you can scratch the other two books off your list.
Enjoy the music.