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FAMILY RELATIONSHIPS

Capitalize familial names when the relationship is considered part of the personal name or when the relationship alone is used as a proper name:
            Uncle Bob
            Cousin Snowie
            Mother, Mom, Father, Dad
            Godmother

Do not capitalize the family relationship when it is preceded by a possessive pronoun:
            her cousin Snowie
            my mother

Set off the name with commas when only one person bears the relationship:
            his son, Robert, came too (only son)
            his son Robert came too (more than one son)
            my wife, Michaeline, came too