The Girl in the Tower by Katherine Arden (Winternight Trilogy #2) / ★★★★☆
Summary: Vasya, now a young woman, is forced to choose between marriage or life in a convent and instead flees her home—but soon finds herself called upon to help defend the city of Moscow when it comes under siege.
“Every time you take one path, you must live with the memory of the other; of a life left unchosen. Decide as seems best, one course or the other, each way will have its bitter with its sweet.”