The Princess and the Guards Captain (lesbian stories)

When Princess Kaitlynn, the eldest of three sisters and fairest of them all, learns what her father has in store for them, she hates him. His decision to marry her sisters and her off to the men of his choice. She's furious, but cannot do anything, but accept her fate. Her sisters seem content with the choices made. Kaitlynn envies them, not for their soon to be husbands, but for the obvious compatibility.
But the choice her father made for her... How can she marry the Guards Captain. How can she marry anyone. Her heart has never been in love. Does the kingdom really require her marriage?