member of family
(5) “member of family” means the spouse of an employee or annuitant and an unmarried dependent child under 22 years of age, including— (A) an adopted child or recognized natural child; and (B) a stepchild or foster child but only if the child lives with the employee or annuitant in a regular parent-child relationship; or such an unmarried dependent child regardless of age who is incapable of self-support because of mental or physical disability which existed before age 22;