1.susan barker . 2.richard barker . 3.jim and don . 4.sally . 5.john and sally are cousins. 6.william . !

1) Susan Barker is William's wife.
2) Richard Barker is Margaret's husband.
3) Jim and Don are John's brothers.
4) Sally is John's sister.
5) John and Sally are Jim, Mary and Don's cousins.
6) William is Richard's brother.