Absolutetrash's manga / #lady knight(2)

MC is abandoned by her noble family and forced to fight as a knight in war. Years pass, and she is captured by the enemy. The enemy’s king takes a liking to her intellect (literally).

After her father passed away and her brother ran away, MC, Leah, is the temporary head of her household. To keep the position she must get married. The lord of another household’s elder brother? Is he related to her mysterious childhood friend?