Hi
Since it was standard for working class girls to begin their working lives usually around 12/13 or younger and that working life particularly in London, was commonly as a servant, then by the age of about 21 which was Catherine's age at the time of the 1841 census the chances that she was living at home are unfortunately much slimmer.
Adult ages, those over 15, were usually rounded down to the nearest 5 on the 1841 census.
No death registered in St Giles registration district between 1841-1851 of a John Mul(*)
Regards
Valda