Betty was the daughter of James Thornley, the illegitimate son of Ellis Mather. This caused confusion as to what her name should be. She was brought up as a "Mather", and used that name for the 1851 census and recording her childrens births, later changed to use the name "Thornley" after 1859 and on the 1861 census.
In 1841, Betty Mather (25) was in Little Hulton with Ann (6), James (4) and Joseph (11 months).
In 1851, Joshua Grundy (head, 42) was with Betty Mather (36, Servant) and 6 children shown as lodgers at Dunkirk, Hittle Hulton: Ann (15), Thomas (12), Joshua (10), Sarah (8), Mary (3) and Ellen Mather (1), all born Little Hulton.
In 1861, Betty was named Betty Thornby and all the children were named Thornby, not Mather or Grundy. However, all births between 1851 and 1861 are mother (and father) named Mather, so all are illegitimate, probably Joshua Grundy's who Betty is still living with.
In 1871, Betty (52) is now named Betty Thomley. She is still with her 5 youngest: Mailce (19), Martha (18), Robert (16), William (14) and Sarah Jane (12).
Betty died, May 1878, aged 63 and buried as Joshua Grundy's wife in the same grave.