Her maiden name might be Cornwell as a John Cornwell gave her and her husband land in his 1674 will.
Margaret married John TURNER  [MRIN: 6641], son of William TURNER  and Unknown, about 1670 in , , Maryland.1 (John TURNER  was born before 1650 in , , ENG and died on 9 Jun 1705 in Foldland, All Hollow's Parish, Anne Arundel, Maryland 1.)
Margaret next married Richard SHAW  [MRIN: 6645] on 2 Oct 1706 in All Hallows Parish, Anne Arundel, MD.1
1 Colonial Families of the United States; Ancestry (www.ancestry.com).
2 Public Member Tree (www.ancestry.com).
3 Pedigree Resource File (www.familysearch.org).