Maybe she wasn't intentionally sneering, maybe her face was like that because her hair is pulled back way too tight...
that's a powerful sneeze to be pressing her against the ceiling like that!
Maybe she's miserable and unfulfilled and has to sneer at other people to stop the desperate, unstoppable sobbing that she is barely able to suppress.
Just a thought. She looks that way.
Maybe she was sneering at something earlier when the wind changed. Her face stayed that way.