'A Sarah Titus m. Rehoboth 16 Aug. 1716, as his third wife, John Garnsey Sr. ... Sarah (Millard) Titus thus appears to have taken John Garnsey as her second husband and to have died by 1723.'
See this article for the argument that the Sarah Titus who married John Garnsey was Sarah (Miller) Titus, the widow of John Titus. The evidence is circumstantial, but substantive.