What led Catherine Tekakwitha to her death

In 1679, we read: “And the almost continual headaches¹ and a stomach illness² at the last year of her life, which was accompanied with vomiting and finally with a slow fever. Her incommodities were increased everyday at the end of 1679, and sometimes we had seen her standing, although she was not able to leave her lodge.”
–Father Chauchetière (1679)

“She had exhausted her strength, which she had fell very more ill the same summer and scarcely escaped death. She had retained a great pain in her stomach and accompanied with frequent vomiting with a low fever that gradually undermining her, which lessened her to a condition of weakness from that she was not able to raise herself. She was very infirm and nearly always ill, which about a year before her death that a great illness had left her with a slow fever and a severe pain in the stomach.”
–Father Cholenec (1679)

¹ Headaches are an indication of continuous poor, or diminished eyesight. The smallpox virus often causes blindness and death. Other complications are diminished eyesight that does not support strong light and pitted scars from pustules. The scars that last for life may remain on the face.
²Abdominal pain (with nausea) is not a specific symptom that could be associated from many conditions. Some abdominal pains do not come within the abdomen but give abdominal discomfort. The list of indications is infinite. Though one indication is gastroenteritis and is the inflammation of the stomach and intestines caused from a bacterial, or viral infection. The symptoms of gastroenteritis are nausea (an unpleasant sensation in the stomach and often having to vomit), vomiting, diarrhea and fever.