A Member's unmarried child who is 6 months of age but less than 19 years old; 19 or more years old but less than 23, enrolled in a school as a full time student and primarily supported by the Member; 19 or more years old and primarily supported by the Member and incapable of self-sustaining employment by reason of mental or physical handicap. The Term "child" means a child born to or legally adopted by the Member. The term includes a child during any waiting period prior to finalization of the child's adoption. It also means a stepchild living with the Member.