Hi Carol,
There are lots of Cary burials in He(u)rstmonceux between 1700 and 1740 (the years I checked) but the only details given are the name of the person and the date, occasionally widow of... In some of the earlier ones though it mentions that the person died at the Hay Harvest!
Thomas was 17 years old when he was baptised in 1733, there was an Elizabeth baptised in 1728 who was 'about 25'.
As for Martha - there is no other information, nor for Thomas (6 Feb 1723/4).
They married 15 January 1708/9 - her maiden name was Delves. She was probably the Martha Delves, baptised at Herstmonceux 12 September 1684, daughter of Joseph and Mary Delves.
Hope this helps.
Liz