Lieutenant Marlena Moreau was a female Human Starfleet officer who lived during the mid-23rd century. She served in the sciences division aboard the USS Enterprise under Captain James T. Kirk, during his historic five-year mission.
Moreau was newly assigned to the Enterprise in 2267, where she made the acquaintance of Captain James T. Kirk a week later. The captain was initially flustered, as he had just met her counterpart from a parallel universe, who had served as his counterpart's captain's woman aboard the ISS Enterprise.
Spock noticed Kirk's surprise and asked if they had met before. Kirk explained that they hadn't, (which was technically true) but that she "seemed a nice, likable girl" and he thought they might become friends. (TOS: "Mirror, Mirror")