And this could be them on the 1841 census, but no Mary unless she is "Margt" (that's what it looks like to me, anyway):
https://www.ancestry.co.uk/interacti...=successSource
High St, Ancoats, Manchester
James Fitzpatric 40 Cotton I
Cathn Do 35 Do I
Ann Do 15 Do Y
Margt Do 12 Do Y
Jno Do 10 Y
Isabella Do 8 Y
Cathn Do 6 Y
James Do 4 Y
William Do 2 Y.