Why does Thomas, Maddy's father, keep her hidden away in the novel, The Weight of Blood?

Late in the novel it is revealed that Reba (Maddy's grandmother had telekinetic powers like Maddy’s. These powers skipped over her, and he hoped they would skip over Maddy as well, but from the day Maddy was born, he knew that she had the same powers as her grandmother. Distraught, Thomas tried to kill Maddy multiple times to get rid of this evil, but he was always too weak to complete the task. Thus, he raised her in a very strict environment with what he believed were good morals, in an attempt to override the evil he sees inside of her. Once Maddy learns all of this, she learns that it was not her mother that Thomas was trying to protect her against but rather the evil she inherited from his family.