I read this book back in early 1980's. Can't remember the title or author.
Colonists to a new planet. Unable to have children until 6 children were mysteriously born. 3 males and 2 females. 1 child was both. The founding rulers decided to operate to make the last one female. The six children had unique relationships with each other and nature. Each child had an affinity with one aspect. Sun, moon, water, etc. Eventually other children were born naturally and the original 6 were ostracized.
This sounds like Sunwaifs, a novel by Sydney J. Van Scyoc from 1981, which deals with the colonization of a planet called "Destiny".
From a summary on Goodreads:
Nadd is our first narrator and he begins by telling us about how he worries for the new generation. He recounts the hardships the original colonists had to endure their first years on Destiny--a planet that had seemed at first so perfect, but quickly proved itself to be anything but. His intentions is to leave a logbook for the next generations so that they may be able to avert the disaster he sees brewing. To this end he asks an... aquaintence of his for help in writing the log book. I hesitate to call them friends, or companions, because in truth the six original 'Sunwaifs' aren't really.
Each original Sunwaif has an extraordinary gift, bestowed upon them while in the womb by the radiation of Destiny's sun. This both saved them and cursed them, marking them as different in a world of dogmatic people who had given up hope and nutured their bitter, hard lives.
As the story unfolds we meet the other four Sunwaifs--Feliss, Trebble, Ronna and Herrol--and watch as each matures and wants different things. But always are they connected, by a bond they can't break no matter what.
The "sunwaifs" were the first generation of the colonists' children to survive. Three are indeed male, two female, and one is neither (or both).
The book is available for free loan from the Internet Archive.
