Eliza Stollard
Her surname is spelled many different ways (Whitehorn, Whitehorne, Withorn, Witbom, Whitham, etc.) in different sources, but the "Whithorn" spelling is found in the 1870 Utah census.
Her death date and place of death are confirmed by her obituary.
Eliza and Joseph sailed to America in 1856 on the ship Thornton, and their surname is listed as "Witham" on the ship manifest.