A likely candidate for a sibling to William DeMoss is Polly DeMoss Harmon. Marriage records from Fleming County, Kentucky have Polly marrying Thomas Harmon in 1814. The family resided in Fleming County until the early 1830s at which time they migrated to Daviess County, Indiana. This is the same time period that William DeMoss’s family also relocated out of Kentucky. Polly is believed to have died sometime between 1839 when her daughter Fannie was born and 1843 when Thomas married Rachel Baker Gibson. A line by line search of the 1840 US Census did not find an entry for Thomas Harmon which would have provided some insight for a more exact date of death for Polly.

Polly and Thomas had at least seven children during their time together. It’s possible that there were a few more as there is a large gap between William (b. 1819) and Matilda (b. 1829). According to the 1830 Census, there could be two daughters born in the 1820s that have not been accounted for. The children that have been documented are:
- Elizabeth (1814-) m. Alexander Moren/Moran/Morin
- Hannah (1816-1902) m. Jacob Hedrick
- William (1819-1884) m. Indiana Alford
- Matilda (1829-1860) m. Lewis Isham
- Rebecca (1831-1859) m. William Edwards
- David (1836-1870) m. Lavina Hedrick
- Fannie (1839-1920) m. William Edwards
Thomas remarried in 1843 to Rachel Baker Gibson and added three more children to the family, Lavina, Robert and Lucinda. In 1860, Thomas is living with William’s family in St. Clair County, Missouri. The younger children are not living with them and Rachel cannot be located.

