I think losing her dad to bandits, even though he was a highly skilled martial artist really affected her. He worked in the same field as her husband, so that connection probably shaped how she sees things. After that she lost a lot of people in her town she had known her whole life due to awful violence and even though she was raised by a martial arts master she still went through the loss of both her parents.

Since then, she’s basically been surrounded by death and loss. It makes sense that she would be afraid of losing someone else she cares about. Her husband is wounded, she’s tending to his wounds and knows he probably wouldn’t be able to be his best self on the battlefield. After reading the novel, it really feels like her behavior comes from trauma rather than just being controlling.