(written from a Production point of view)
Carey Foster is an actress and dancer, who appeared as a background performer in several episodes of Star Trek: The Original Series. She received no credit for her appearances, but her name was included on call sheets. 
Foster appeared in smaller roles in films and television projects throughout the 1960s. These include three episodes of Gene Roddenberry's series The Lieutenant, which starred Gary Lockwood. She can be seen in the 1964 Elvis Presley film Roustabout (with Marianna Hill, Lance LeGault, K.L. Smith, and Terri Garr), the teenage comedy Pajama Party from the same year (again, with Teri Garr), and the 1967 thriller Point Blank (with Michael Strong, Sharon Acker, James B. Sikking, Sid Haig, Michael Bell, Jerry Catron, Chuck Hicks, and Felix Silla). In 1969, she worked as assistant choreographer on the Jack Benny's Birthday Special TV program.