What happened to Jean (the little girl) because of the dust storm?

The dust storm is regarded as one of the worst environmental disaster in America.

The dust storm made tiny dust particles drill into Jeanne's lungs. She came down with dust pneumonia, the brown plague. Emergency centers were set up by the Red Cross in Kansas, Colorado and Texas to deal with the rise of respiratory infections.

Her mother visited her at Colorado and the doctors told her that her Jeanne could die of the pneumonia.

Jeanne eventually survived and recovered from it.