Hi Lisa
Are you sure of the dates? The reason why I ask is that Grouville Church records didn't start until 1584. Having spoken to the Societe Librarian, she like me, is interested as to where you got the dates from (IGI?).
As an aside, they have lodged with them a large Mallett of Grouville family tree which goes back to the 1600's and from which I can give you details if there is a connection.
Stewart