Hello Snazzy
Just a little piece of information which might help. I'll start with the earliest date so please bear with me:
On 29 Oct 1826 Caroline Amelia PULLIN, dau of John and Sarah (Maria) PULLIN was baptised at Kintbury, Berks. At the time of the 1841 census Caroline was a servant in the household of Charles GOODHART, a clerk, in Castle Street, Reading. On 15 March 1846 she married Henry COOPER at St Dunstan, Stepney and they subsequently move to Windsor where, according to the census, Henry had been born. Whilst living in Windsor they have a number of children, including Louisa who was born about 1854.
In the December Qtr of 1876, Windsor Registration District, Louisa COOPER married Frederick William CONNOR. A few years later, in the March Qtr of 1880, Eton Registration District, Caroline Amelia COOPER married Peter CONNOR. So, when Caroline and Peter are living with Louisa in 1901, Peter is correctly described as Louisa' father in law as this was often used instead of step father. Caroline, however, should have been described as Louisa's mother.