The Keeper and the Rulership - Emily Martha Sorensen

As the daughter of a landowner, Raneh lives in a world of clearly defined roles and rules.  She's supposed to get married, gain status, become a landowner herself, and definitely not have magic.  Seeing as it's forbidden and all.

Too bad she has it anyway.

On top of that, a suitable courtship does not seem to be forthcoming, her younger brother is a social embarrassment, her younger sister is better at everything than she is, and . . .

And the Ruler's coming to visit.