Reddit mentions of Prophecy of the Sisters (Prophecy of the Sisters Trilogy, Book I)

Prophecy of the Sisters by Michelle Zink?

> Grade 7 Up—Lia and Alice buried their father on a rainy day in the fall of 1890. His death was sudden, and strange happenings are keeping the twins from resuming their wealthy, well-educated lives. Lia begins to dream of flying and Alice, while reserved, does not appear to mourn her father. Lia's boyfriend, James, uncovers an ancient tome that cryptically tells of two sisters, one the Gate and one the Guardian. One has the power to return Satan to Earth, the other the responsibility to keep her sister in check. As Lia investigates the prophecy, a fortuitous trip to a fortune-teller, Sonia, unlocks new doors. With school friend Luisa joining in the adventure, the cast of characters is complete. Lia, Sonia, and Luisa band together to solve the riddle while preventing the increasingly malevolent Alice from discovering their findings. [...]

• Cara von Wrangel Kinsey, formerly at New York Public Library (full review on Amazon)
  
  Lia and Alice were born by cesarean which caused them to be born in a different order than the prophecy had intended and therefore their roles in the prophecy were switched.