I have pre-1855 burial index - I just got it yesterday, for Muiravonside, and Polmont is in the same volume...
It has:
Nothing for a Helen Henderson in the 19th c.
Gaff, Helen, buried 14 sep 1833, (abode) 'Lauriston', mortcloth listed as 'best'
Gaff, James, - 3 burials listed in the 19th c., all with abode 'Redding'
18 jul 1829, no mortcloth payment
4 jun 1836, no mortcloth payment
21 jul 1837, no mortcloth payment
Gaff, James, buried 6 Oct 1828, of 'Little Kerse', no mortcloth payment
There is no further information in the index I have.
Hope you may find them here! I had a quick look at Henderson 'abode' names and the farm or village names given for Henderson deaths do include Redding and Lauriston. I don't know Polmont at all though, so can't help further with the area.
Jenny