The FL has red hair and is the older sister. Her younger sister is blonde (possibly named Diana) and is believed to possess holy/healing powers, but the power actually belongs to the FL. The younger sister refuses an arranged marriage to the black-haired Duke of the North because she wants the Crown Prince and talks about being a "revolutionary woman." The FL marries the duke instead. The northern territory suffers from a blight, and the FL's power becomes important. Later the younger sister becomes obsessed with her sister's husband. There's also a memorable charity event where the FL organizes a fundraiser among nobles, the younger sister criticizes it as not helping the people and tries to take over, but completely fails.
The FL has red hair and is the older sister. Her younger sister is blonde (possibly named Diana) and is believed to possess holy/healing powers, but the power actually belongs to the FL. The younger sister refuses an arranged marriage to the black-haired Duke of the North because she wants the Crown Prince and talks about being a "revolutionary woman." The FL marries the duke instead. The northern territory suffers from a blight, and the FL's power becomes important. Later the younger sister becomes obsessed with her sister's husband. There's also a memorable charity event where the FL organizes a fundraiser among nobles, the younger sister criticizes it as not helping the people and tries to take over, but completely fails.