It might be better if we work back from what you know - when and where are the family in St Helens
In 1901 Lucy is at 96 College Street, St Helens
Lucy Smith
age 64 bn Norwich a Widow living with her son Charles age 33 bn Newcastle on Tyne
In 1891 is a housekeeper
age 57 bn Norwich living Parr, St Helens
In 1881 as you said
Lucy
age 50 bn London, Middlesex
Lucy dtr age 17 bn Norwich, Cheshire (Could always be Northwich

)
Charles age 14 bn Newcastle