"she has consumption and very bad"

Consumption is another word for Tuberculosis (TB). It usually attacks the lungs and spread through the air when those with the disease cough, sneeze, or spit. When TB goes untreated, like in Sally Jean's case, it kills more than half of those who have it. Symptoms of TB include coughing, fever, night sweats, and weight loss. 

Source: Wikipedia - Tuberculosis