A genealogy article in the Times Dispatch of Richmond, Virginia, dated December 15, 1912, gives some context to the extended Martin family. The article notes that Elizabeth was a daughter of Pleasant Martin, Sr., that she married William Powell, and that she and William had six children. The children are noted as Mary, Mildred, Rebecca, Sarah, William, and Jane. 
While Elizabeth ("Betsy") and William were married in Virginia in 1805, sometime after that, the couple moved to Missouri.  Elizabeth died in Missouri in 1872, and was buried in Jopling Cemetery in Pettis, Missouri. 
"Pedigree Resource File," database, FamilySearch (https://familysearch.org/ark:/61903/2:2:STS7-D66 : accessed 19 August 2019), entry for Elizabeth /Martin/; file (2:2:2:MMQS-4Y4), submitted 12 May 2011 by gregorya3 [identity withheld for privacy].