Margaret’s maiden name is sometimes listed as Herrington. An 88 year-old Joshua Herrington and wife Elizabeth (77 years old) is listed right next door to the Stowells in Lamar Co., Texas in 1850. However, the marriage record for Willard Stowell is to Margaret Ryason. There is also a marriage record for an Elizabeth Ryason to Joshua Herrington. There is a Betsy Ryason who is the head of household in the 1820 census living next door to Joshua Herrington. Betsy has female children, one of whom is the right age to be Margaret. Could it be that Betsy is the Elizabeth Ryason who married Joshua Herrington and one of her daughters, Margaret, by her Ryason marriage married Willard Stowell?