Discuss the character of Mrs. Fellowes?

Edith Fellowes is smart, knowledgeable, and well versed in the scientific method, making her well equipped to understand the implications of the events of the story and the hazards of her own actions. The fact that she has an analytical mind is evident early on as she makes careful, pointed observations of those around her, most notably Dr. Hoskins, whose looks she quickly assesses. We also learn that she is prone to judge people by their looks, a bad but common trait among people, and an essential one for the plot of this novella. She notes defensively that Dr. Hoskins is unattractive. This element of judging people by their looks is emphasized by Dr. Hoskins, who asks "do you just love pretty children? Nice chubby children with cute little button-noses and gurgly ways?"

When Edith hears "a terrified scream from the dollhouse rooms," she rushes to the aid of the child, but "It was the ugliest little boy she had ever seen." The boy has a flattened and receding forehead, the back of his head bulges, and he has no chin.
Edith is repulsed by the boy's appearance, and her first thoughts are to flee the premises, but she then remembers Dr. Hoskins's question, "Only pretty children, Miss Fellowes?"

Over the course of the story, Timmy is put under Edith's care. She must bring him toys, sing to him, read to him, bring him video and music tapes, and eventually provide him with a playmate. From resolving to stay with Timmie only as long as it took to settle the child comfortably in his bubble and then quit, Edith Fellowes becomes first a nurturer and then Timmie's mother by the story's end.