Why a mother would keep her child hidden in a closet?

I read a story about a little who was hidden away in a closet by her mother in Kansas City, the mother didn't give her daughter any food or water or even for to go out and play or go to the restroom, the Kansas City police went to the apartment and asked "Is anyone here?" and the little girl answered "yes" the police found her in a closet with mutiple healing skin injuries, and failure to thrive. The child told the police that her mother got mad at her and punched her on the back and the mother claiming that she only has tow children but failed to mention that she has a third child in her apartment hidden away in a closet with no food to eat or water to drink, the mother's boyfriend claimed that he didn't know that was being malnorished but he and the mother where arrested for child abuse in the first digree, i just that the mother will spend the rest of her life in prison and lose her rights and not have no contact with her other children because i believe that the little has been put through enough child abuse, and i just  hope that she and her siblings are put into good and loving and caring foster homes.