The widowed Doctor Crusher juggles the responsibilities of raising her son alone while also serving as Enterprise's Chief Medical Officer. Crusher, along with her later husband, had been acquainted with Captain Picard long before joining its crew.
Wesley lost his father at a young age and was raised alone by his mother, Beverly Crusher. Both of his parents had been acquainted with Captain Picard long before Wesley came aboard the Enterprise. Extremely intelligent and dedicated, Wesley eventually gains a field commission of Ensign before leaving to attend Starfleet Academy.
After his parents were killed in a Romulan massacre, Worf was raised by humans and became the first Klingon in Starfleet. He was promoted to Chief of Security in TNG's first season, following Tasha Yar's untimely death. Worf later leaves the Enterprise to join Deep Space Nine.