My files show: d/o 3George and Mary HELLINGS DUNGAN:
4Sarah “Sally” b.8/25/1742, d.1815 Knox Co TN,m.1761(age19/21)in Frederick Co, VA, Robert LUCAS b.1740, d.1781 shot by Indians at Freeland’s Station VA, 8 children (no names listed)
You may want to try the Frederickl Co VA records rather than the Frederick Co MD records. I believe I pulled this date and the ages from those files. The number of children was picked up from a descendent entry on Ancestry.com.