Source 1. New England Marriages Prior To 1700:
Source 2. Genealogical Dictionary Of Early Settlers Of New England by Savage-pg:251;
Source 3. Ancestral File;
Source 4. Early Settlers Of Essex & Old Norfolk-pg:33-lists a Hannah Gilbert ae. 24 in 1670. Might be this Martha.
Source 5: Fifty Migration Colonists To New England & Their Origins:
Source 6: Genealogical pamphlets on Five Smith Families by Frank J. Wilder:
Some sources claims This Marthas last name is Knowlton, but no marriage is recorded in Ipswich Records for a Martha Knowlton. Perpahs Martha married a (Mr Gilbert) prior to her marriage to Thomas Smith; The work has been done for Martha Gilbert & Martha Knowlton; She is not our direct line, so I am not going to pursue this discrepancy!