grandniece-by-marriage
Spouse's grandniece.
My grandniece-by-marriage is a good person.
great-grandniece-by-marriage
Spouse's great-grandniece.
My great-grandniece-by-marriage is a good person.
grandniece-by-marriage-in-law
Spouse's grandnibling's wife.
My grandniece-by-marriage-in-law is a good person.
great-grandniece-by-marriage-in-law
Spouse's great-grandnibling's wife.
My great-grandniece-by-marriage-in-law is a good person.