(6)Or is made in will or deed relating to family affairs. - When the statement relates to the existence of any relationship [by blood, marriage or adoption] [Inserted by Act 18 of 1872, Section 2.] between persons deceased, and is made in any will or deed relating to the affairs of the family to which any such deceased person belonged, or in any family pedigree, or upon any tombstone, family portrait or other thing on which such statements are usually made, and when such statement was made before the question in dispute was raised.
