The Builders by Ellen Glasgow

In the breakfast room next morning, Caroline found the little girl in charge of Miss Miller, the nurse who was leaving that day. Letty was a fragile, undeveloped child of seven years, with the dark hair and eyes of her father, and the old, rather elfish look of children who have been ill from the cradle. Her soft, fine hair hung straight to her shoulders, and framed her serious little face, which was charming in spite of its unhealthy pallor. Caroline had questioned Miss Miller about the child's malady, and she had been reassured by the other nurse's optimistic view of the case.

"We think she may outgrow the trouble, that's why we are so careful about all the rules she lives by. The doctor watches her closely, and she isn't a difficult child to manage. If you once gain her confidence you can do anything with her, but first of all you must make her believe in you."