Tracing Elizabeth Shepherd (lady below Rebecca) and her son backwards.....
It appears from the GRO index that MMN for young Robert is Massingham.
There is a marriage in 1841 for a Robert Shepherd and Elizabeth Massingham in Aylmerton. Robert is a Shoemaker.
It looks like Mar is crossed out on the census entry for Elizabeth and Wid or something similar written instead. I think her entry was originally meant to be Pauper Wd (of) Ag Laborer but the Ag Lab was crossed out and replaced by what looks like it could be a badly written Shoemaker, as suggested earlier.
PB
Edited to add: there is a death recorded for a Robert Shepherd in 1845 in the area they were living.