Yeoman Tina Lawton (2266)
Tina Lawton was a yeoman third class serving in the sciences division aboard the starship USS Enterprise in 2266. Yeoman Lawton was introduced to Charles Evans by Janice Rand in an attempt to get him to get to know someone his own age. He snubbed her, and later used his Thasian powers to turn her into an iguana. When the Thasians reversed all of the crewmembers that Charlie had changed, she was restored to her human self. (TOS: "Charlie X")
Background
Yeoman Lawton was played by Patricia McNulty. Yeoman Rand introduced her as someone Charlie's own age, and he was seventeen. However, most later Trek productions portrayed Starfleet as generally being an eighteen-plus organization (although Wesley Crusher and Peter Preston were both supposedly 15 years old when they entered fleet training). Yeoman Rand could also have been generalizing.