Beyond what Billie says, why do you think she feels that she doesn’t belong in the same world as anyone else she knows?
She experiences the world differently and doesn’t see herself reflected in others. She is processing a combination of neurodivergence, grief, and emotional isolation.
Whether she is or isn’t on the autism spectrum isn’t absolutely clear; however, the author gives Billie characteristics and behaviors that suggest she might have been if the condition was known at the time of the setting. She was brilliant. She interacted in life differently. She carried Charlotte within her perhaps as a coping mechanism. I also believe both of her parents had their oddities, and they were role models.
Billie was growing up in a time when children were all expected to conform. Billie could not. I would love to think that a child like Billie would have an easier time today, but often people don’t see that different is not wrong.
I think Billie was treated as if she didn’t belong. Her world was different from the people she was around.
Because Billie’s thinking patterns are very different from most people. I think this is very frustrating for her because, although she tests at the genius level, she cannot grasp why the world is so foreign to her. Her situation is made worse because her mother does not try to help her navigate through life but, instead, lets her flounder. Had her father lived, I think he would have given her more of a sense of self worth and acceptance.
She was different from the people she knew and unfortunately was not treated kindly.
Most people put Billie on the periphery. If there’s no one else around she’s good enough to associate with, but if others are available then they either ignore or exclude her. Billie may have been on the spectrum, but she also had feelings like all of us.