I know the main character was Cassia. I think they called her Kiska or Ciska affectionately.
Her type of magic was shunned, but wizards were revered. She was taken on as an apprentice type by a head wizard type who eventually goes bad. She puts together pieces of knowledge to blend elements to travel distances and time. She eventually helped the king.
She had a son (Beya? Benya? Beyja?) and a love interest in the book. There was also a historical character named Marija Ohdani or Odahni?
This wasn't a best seller by any means as far as I remember, and I believe this was in the 90's but I'm not positive.