You may be thinking of Everything's Coming Up Roses.
From Baka-Updates:
Abducted from her mother at a young age and tortured for her incredible power, Evanna knew nothing but agony her whole life. That is until one day, she is rescued and returned to the father she never knew, the Duke of Vicente. But as Evanna's very existence brings back painful memories for the Duke, he must learn how to love her, while Evanna must come to trust her father and heal her trauma. But with Evanna's power highly coveted, can these two overcome their thorny pasts for a rosier future?
The protagonist, Evanna, was taken from her mother by the king's men as a child, held prisoner, and gradually drained of her magical power, before finally being sacrificed on a platform on top of a hill. She then wakes up again as her three-year-old self, remembering everything that happened in her previous life.
As before, the king's men take her away from her mother and imprison her once more, but this time someone wearing a hood and mask frees her from her prison cell, and she's subsequently taken to the lavish home of her estranged father, Duke Vicente, by a friend of her mother.
Although Evanna is well-treated at the duke's estate, she's extremely fearful of everyone who approaches her, due to the psychological trauma resulting from the abuse she suffered in her previous life. Shortly after moving in, she's assigned a female psychiatrist to help her work through the trauma.
The duke also has two other children, a boy and a girl, who play with Evanna in subsequent chapters. Evanna has blonde hair, and the story takes place in a medieval setting.
