What is the tone of The Giant's House by Elizabeth McCracken?

The tone of The Giant’s House, by Margaret McCraken is tragic due to its themes of survival of the misfits, and unrequited love.
Peggy Cort, the narrator, is a tiny librarian in a small New England town, who feels that her life and chance for love are passing her by. She befriends a young boy who visits the library looking for books on how to halt his growth. James Carlson Sweatt is an abnormally tall boy which renders him a social anomaly. From the unusually tall boy he grows to be the tallest man in town, towering over eight feet. Both of these characters try to find ways to fit into society but find acceptance in their friendship and books. Peggy comforts James when he loses his mother, and takes him off to New York City to join the circus. Ultimately, they fall in love but are unable to consummate that love, and James dies soon after. Peggy is once again left alone and lonely. She says,

For years I'd waited for someone to love me: that was the permission I needed to fall in love myself, as though I were a pin sunk deep in a purse, waiting for a magnet to prove me metal. When that did not happen, I'd thought of myself as unlovable.
...It was this I'd waited for all my life: a love that would make me useful, a love that would occupy all my time.

Peggy goes on to have a child which she passes off as James’s child, thus keeping his memory alive for all who shunned the two of them as social pariahs. Although this book is a love story, a story of social acceptance, it is a tragic one.