I am really getting nowhere with this search. Mary Percivall married Edward Davies (variously described as a 'brewer' and a 'labourer') at St Peter's on 26th April 1789 and that is the only date I can find for her!
Mary and Edward had 7 children between 1790 and 1804, all being baptised at St Nicholas's. From 1790 they lived in Preston Street (previous addresses being Dale Street, Fontenoy Streer and Webster Street.
Mary was widowed in 1803, a few months before the birth of her last child, son Edward.
Can anyone help me find a likely birth or death for her, please?