According to Binnie (German Baptist Arnolds, p. 44), Sarah's stone in the Beaver Run Cemetery shows "Sarah Leatherman, wife of Benjamin, d. 25 July 1910, age 85y 11m 28d". This would put her birthdate at 23 July 1824, which is in conflict with the birthdate for her brother David implied by his stone (3 Aug 1824). Since he died young, and since there is no "carrying" between months and years involved in the calculation of his age at death, it is more likely that his age is the correct one. One possibility is that they are twins, and her stone should have said 85y 10m 8d (someone made an error of 10 days in calculating her age at death.) Another possibility is that Sarah was born in 1823, though that would mean two children almost exactly a year apart, which is very close spacing, especially for a 42-year-old mother. I am tentatively entering this as her birthdate. It might be helpful to look up the Benjamin & Sarah Leatherman family in the 1880 census.