Some information from Findagrave.1 Something about this birthdate is off. If it were as calculated on the gravestone, she would have been born in 1810, which is the same year and month as her brother William Knorr. Either they were twins or the year is wrong. The 1830 census seems to show both are at home with the eldest daughter slightly older (maybe by a year or so) than the oldest son. Anna’s birth year has been updated to 1809 as a result.