Hi -
I think I have the family in 1841 census, Guernsey, but the enumerator is a bit mean with the details:
1841 Guernsey, St Peter Port distr. 4, page 1, piece 11, folio 26
No.1 Commercial Arcade
A.B. Goupillot 38 Grocer b: France
Mrs S Goupillot 30 b: Guernsey
Anne 7
L [female] 3
Augustine 2
Unfortunately I did not find JPVF Goupillot.
Mike