Unfortunately if people died before 1851, it is very difficult to find where they were born and therefore who were their parents.
I think they may be found in the 1841 census
Do you have access to Ancestry or Findmypast ?
In St Mary Whitechapel, a Sarah Stenson aged 42 with Mary, 15, Martha 6, George, 8, Samuel Stenson, 4 and Henry 22 and Sarah 18. This 1841 census does not quote the relationship but the fact that the names george and Henry appear is a good sign. I do not understand why the youngsters are quoted in disorder but it seems her 2 first children were named after her and her husband Henry. 3 children are baptised in St Botolph in 1842 but their dates of birth are 1834, 1836 and 1838.
Henry Matthew died in J1841 in Whitechapel. There is the death record of a Sarah Mary Stenson in 1849 but her age is given as 41... A mistake ??