"convinced she was consumptive"

Consumption, or pulmonary tuberculosis, was a widespread disease in Victorian times: just one London hospital treated between 6000 and 7000 cases a year in the 1860s (source).  It is a stereotypical cause of death for heroines of the 19th century: examples include Satine in the film Moulin Rouge; Mimi in the opera La Boheme; Fantine in Hugo's Les Miserables; Beth March in Little Women.  The symptoms include fainting, fatigue, paleness and coughing up blood.