Able seaman Carter was a female Starfleet crewman who served during the late 23rd century. (Star Trek VI: The Undiscovered Country)
Carter's name comes from the name tag that was included along with a Starfleet uniform sold on It's A Wrap! sale and auction, as well as an individually sold name tag. [1]
She was played by one of several unknown actresses who served aboard either the USS Enterprise-A or USS Excelsior.