She was an orphan traveling with the John Murdock family and is listed on the roster as "Mary C. Murdock."  She is the daughter of George and Alice Cooper.  In the 1850 Utah census she is five-year-old Mary Cooper in the household of John Murdock.  In the 1860 census she is in the household of John R. Murdock.  On the Utah Death Registers, her Utah death certificate and the Find A Grave website she is Mary Joice Cooper Goodwin.  She is Mary J. Cooper Goodwin in the Utah Cemetery Inventory.