Shadrack and Sarah had numerous children per the 1820-1850 census records. The 1800 and 1810 census entries for them are missing, so we can't use those for comparison.
I'm not aware of a Will or other record that names their children. David Dugger (c1817) is proven, more or less, by Shadrack and Sarah living with him on the 1850 census.
Thomas J. Dugger (c1819) is proven, more or less, by widow Sarah Hogan Dugger living with him in 1860.
The rest of their numerous children are yet unidentified. Any unattached Duggers born in NC ca 1793-1805 or in TN ca 1800-1825 could easily belong to Shadrack and Sarah.