Might have to go back to basics a bit why do you think Jemima is the sister of your Sarah?
Willow x
I'm asking myself the same question...!?
My reasoning is as follows:
-Daniel Lawton and Sarah Mountford (both my ancestors) married in 1853
-Her father's name was Thomas Mountford.
-Both Daniel and Sarah appear as witnesses in 2 of the 3 marriages of Jemima Mountford.
-Jemima's father's name is also Thomas Mountford
-Jemima appears in the 1851 census with mother Ann, brother Aaron, and sisters Sarah and Harriet.
-The 1841 census includes Thomas Mountford, wife Ann, and Aaron, Sarah and Harriet.
-The 1861 census gives Sarah's place of birth as Chell.
-Baptism of Sarah Mountford in Newchapel gives parents' names: Thomas and Ann.
-Baptism of Jemima Mountford gives also parent's names: Thomas and Ann.
It would help to find the baptism of Aaron and Harriet Mountford,
or a marriage between Thomas Mountford and Ann...