Looking for a two-book sword & sorcery series I read in the early '80s. I think I discovered it via a character write up in Dragon Magazine, so the books likely were published a while before I found them. Feel-wise I think they were too grim & gritty to come from as far back as the 60s. I think it was one story arc over two books rather than two completely separate stories, although there were several discrete sub-stories in the middle. It may have been a fix-up book stitching together a bunch of shorts.
Background stuff. More or less chapter one basics leading to the Adventures
Our Heroine, "Rivka" (<= low confidance. That seems too biblical, but I'm going with it), is a horse nomad shaman-swordswoman and daughter of the clan-chief.
Rivka's magical calling is gender appropriate, but a woman learning the sword is blasphemous. Anther clan ambushes and destroys her clan and poisoned the clan wells.
Rivka and her magic talking horse escape alone to the standard medievalish fantasy Civilized World
Some specifics that I hope will narrow things down
Adventures in civilization frame around a cat & mouse chase with an evil sorcerer. I don't remember how they connected or how it finished (presumably she beat him and was then able to return home), nor if he was chasing her, she was chasing him, or a bit of both. She'd adventure in one locale then move on either in chase or in flight to the next story.
She hooks up with a potential love interest but leaves him because she doesn't want to become civilized enough to settle down with him.
She spends time in an abbey where she discovers that her patron deity is the Warrior aspect of a triple-goddess.
At the end she returns to the desert to prove her acceptance by the goddess. She miraculously cleanses the clan wells fouled in the initial chapters.
Outside of Rivka and the evil sorcerer there isn't much magic, and her magic is primarily low key - divination via rune-stones and healing rather than flashy fireballs. Combat-wise she's primarily a physical warrior.
Meta stuff
I believe I had this shelved on the top shelf of my childhood bookshelf, so the author's name is likely early in the alphabet. I'm highly confidant this isn't Asimov.
My searches keep bringing up Mercedes Lackey. I'm highly confidant this isn't Mercedes Lackey.
I have vague recollections of the book covers being beige or brown with Rivka on her horse wielding a scimitar and dark blue or black with a red splotch - possibly a ruby set lighthouse style in a wizard's tower. The name of the dark blue one may be similar to the "Black Tower", but I'm low confidence on that, and it's not any of the "Black Tower" books I can find record of.