Died at about 6-7 years old. Mary was the adopted daughter of Josiah S. Kelly and Fanny Wiggins (a child of Fannie's sister). Mary Hurley Kelly died while trying to escape after being captured during an attack by Northern Plains Indians. She and her family along with several others were traveling on a wagon train that had started from Eastern Kansas and heading towards Montana. The incident that occurred near Little Box Elder Creek's Crossing in Douglas, Wyoming claimed the lives of four members of their wagon train, plus two people from the Morris-Hasting Train behind them. This incident has historically been called the Kelly - Larimer "Massacre," but this term has since been changed to a more appropriate "Incident."
A heavily biased and theatrical account of Mary's journey and demise is titled: Narrative Of My Captivity Among The Sioux Indians (1871), by Fanny Kelly.
An unbiased nonfiction account giving a bird's eye view on the attacks on more than 67 families affected by the Northern Plains Indians' action is titled Emigrant Tales of the Platte River Raids (2024).
Noah D. Taylor and three others, a Reverend Sharp; a black employee of the Kelly's named Franklin; and another traveler from the Morris train, Arthur Wright, were buried in a single grave, on the creek.
The grave Noah shared with the other three men was relocated during the 1954 construction of a reservoir. Although it was a little distance from the others, Mary was also buried where she was killed. When the other men's grave was moved, they were reburied closer to Mary's grave.

A video exploration of this grave is on YouTube, though many claims stated by the narrator are either incorrect or unsubstantiated: https://www.youtube.com/watch?v=uLXAoJLO1zI