Princess Cirilla was the first born daughter of Queen Cerys I. As such, she assumed the role of crown princess, and would inherit her mother's throne if she remained the sole daughter. From a young age, Cirilla knew how unlikely it was for her to become queen, as her mother was still very young and would rule for years to come.
As time passed and Cirilla grew to understand her mother's position better, she found herself more and more relieved that she wouldn't have to become queen. She was an adventurous, impulsive youth, and had no interest in bearing the grand responsibilities of a ruler. But she was eager to make her mother proud nonetheless. She was, after all, a royal princess.