I remember reading this series from 70's or 80's but I cannot find it. Here is what I remember.
It is sci-fi not sci-fantasy. The protagonist ends up as a space ship captain. She may have been one when the series starts but I don't remember.
She works and/or lives on a planet covered with some kind of fog or mist. People on the planet travel on horses. To navigate it when traveling people follow strings. Learning how to read the strings is a skill that is learned.
A some point a tool is introduced that lets a person alter their body. The person envisions the alterations and then twists the tool which is in the shape of a bar. I do not know if the tool can change gender. What I remember is that it only changes physical characteristics like hair, muscles, skin color, etc.
The planet gets taken over by a fundamentalist group and all the women loose rights to work or travel. They must wear dresses and may be chained. Their bodies are altered by the men in power so they look like Barbie dolls (exaggerated playboy bodies). The women must stay at home and raise as many children as the men impregnate them with.
It turns out that the fog that covers the planet is generated by a computer system to protect the planet. The strings that are physical objects on the planet, are representations of computer strings (algorithms) that the computer generated as navigational devices for residents.
Eventually the planet is freed from the fundamentalists through an uprising the protagonist is involved in. I believe this happens by the rebels finding the computer system that is creating the planet's environment. By the time this happens the protagonist has a young son, I think between 3 and 7 years old.
The protagonist goes back into space with the body altering bar that all people now have access to. She alters her body so that she is a warrior, strong muscles, finger nails the strength of claws that can release poison, enhanced eyesight, etc. Her son goes with her but is still adjusting to the fact that his mother, and the other women on the ship, are now warriors not barbie dolls in dresses.
I would like to re-read the series. Does anyone remember the series or the author?