Martha was born about 1793. Martha Babcock ... She passed away in 1868.
Sources
"United States Census, 1860", database with images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MHRW-JYQ : accessed 12 February 2016), Martha Bennett in entry for Charles Bennett, 1860.
"Find A Grave Index," database, FamilySearch (https://familysearch.org/pal:/MM9.1.1/QVVJ-L5VJ : accessed 12 February 2016), Martha Bennett, 1868; Burial, Mystic, New London, Connecticut, United States of America, Elm Grove Cemetery; citing record ID 22415553, Find a Grave, http://www.findagrave.com.