Sarah's obituary states that she came to Utah in 1850. An obituary for Edward Buys (Sarah's brother) states, "With his father's family he crossed the plains in Capt. David Evans' Company of ox teams in 1850."
More research is needed to verify Sarah's date of birth as secondary sources and indirect evidence state and imply that she was born sometime between 1838 and 1840. The birth date listed above reflects information from family tradition (at Family Tree on FamilySearch.org), Sarah's obituary, death record, and headstone.