The MI that ends with "Mary their daur, & w. of Robert Mavin of Glanton 16-4-1833 age 84" really has helped enormously
Whittingham Burials Register 1833
Page 678, entry 541
Robert Mavin, Abode Glanton, buried 18th April aged 81
and a notice in the Newcastle Journal on 20th April 1833 says
At Glanton, on the 16th inst., aged 81, Mr Robert Maving, joiner
Though his age is slightly out, either the mason got it wrong or the stone was worn and whoever transcribed it mistook the final character for a 4. Otherwise its ticking all the boxes and, as you said, provides a trackable connection to Mary's parents - not that I disbelieved you at all, I just need to also check this out for myself so I am doubly sure before I add her parents to my tree.
I only do baby steps so that's my first one taken. With all the wonderful info its going to be the first step on a very long walk :-)
Thanks again Andrew I am doing the little happy dance here :-)
Boo