I read this somewhere in the later 1990s as a paperback book. The main character, at the start, does Tarot readings in the marketplace. I think there was an early scene where a fight to the death (sanctioned by the government with them being from opposing families who'd paid for the privileges) messes up her reading. She's a former student (from Earth?) who got trapped on the planet because she missed her return flight, and she's hoping to save up enough money for a ticket off-planet. Eventually, she's approached by a local lord who gives her his own deck to read. Satisfied with her reading of it, he hires her. It transpires that he relies on the Tarot readings to guide his business (magic being something that works on this planet), but he's been cursed to be unable to read his own cards. I remember she was none too fond of him at the start, but starts warming to him, at least until an incident where her accumulated money is burned up in a fire at her residence. She's convinced he arranged for the fire to ensure that she wouldn't leave the planet, but she also learns that one of the card readers before her died in a fire, implied to have been caused by a rival who wanted to deprive him of intelligence.
At some later point in the book, she meets his family, including the acerbic grandmother who put the curse on him. She's given the "gift" of an obsidian cat, which I believe is stated to be a handwarmer, but which carries a deadly curse if touched with bare skin. She also meets the lord's brother, who is paraplegic, but intelligent and charming. Something happens that leads to said lord being kicked out of his house. He's either injured or despondent, and largely unresponsive, so she takes to supporting them via her readings. I remember she becomes fond of a coffee-like beverage that someone warns her will stain her teeth. Oh, and when the lord starts talking to her again, it was to complain that she was begging for food (I think she was getting it from a local temple) and there's a comment about it tasting like sawdust. I think she also starts training in a staff-based martial art, maybe named something like The River? I think there's a metaphor going on with the slower Tai-Chi like movements being a slow-moving stream and the acrobatic kicks and strikes being like a set of rushing rapids.
Near the end of the book, the aforementioned paraplegic brother shows up and challenges the lord to a fight to the death for leadership of the family. I think he was using some sort of magic to allow him to walk for a time, which was done by drawing power from volunteers. He has the upper hand in the fight until the protagonist meets him between rounds (they'd been friendly up to that point) and after establishing that he will not back down, she tosses the cat to him. He has a moment of horrified realization as he catches it, before she sinks a knife into his heart, which is considered to be a valid way to settle the duel since she's considered part of the family. She also acknowledges her attraction to the lord, and I think the book ends with her becoming his wife.
One other thing I remember about the setting is that they have weapons named something like "heat pens" that generate a hot spot at the end of them. I think one might have been used in the fight at the beginning and it also showed up later in the book.
I later learned there were sequels, and I know I read one of them, where the protagonist was learning the magic of the world. Other than that, all I recall was that she's kidnapped and near the end, it's revealed that her captor had her under a "love spell", but since the only thing the spell can do is create symptoms, she doesn't realize she's under one, assuming that her increased body temperature and racing heart around her captor were due to fear and adrenaline.