The Anne Roberts, age 20, at Walcot on the '41 Census was born between 1821-1824, allowing for the rounding down of age that applied to that Census.
The address was Lower East Hayes and FindMyPast has the burials (transcription only) of -
Elizabeth Roberts, age 68, 3 Lower East Hayes, buried 20 Jan 1842
Leonard Hayes, age 70, Lower East Hayes, buried 29 April 1847. Leonard's death was reported in the local paper " ... after a protracted illness, borne with Christian fortitude and resignation".
Was Leonard, as a "Stable Keeper", owner of the business or, possibly, an employee of William Carter?. Did Anne step into Leonard's shoes? Need to check for a will.