Saavik

Lieutenant junior grade Saavik was a Starfleet cadet in early 2285, and served aboard the USS Enterprise as navigator under Admiral Kirk during the Genesis crisis. A Vulcan, she had been mentored by Spock at Starfleet Academy. At this stage in her career, she often quoted Starfleet regulations, and was surprised by the way Kirk occasionally bent those rules. Despite her Vulcan stoicism, Saavik was seen to cry at Spock's funeral. 

Later that year, Saavik was transferred to the USS Grissom, where she further studied the Genesis Planet along with Kirk's son David Marcus. There, they found the body of Captain Spock, who was believed lost. When Saavik and David found him, Spock's regenerated body was physiologically that of a child, but he aged rapidly. Saavik helped Spock through the agonies of the pon farr. She returned to Vulcan with the Enterprise crew, to reintegrate Spock's katra into his body in 2285. 

In 2286, she remained on Vulcan when the Enterprise crew, together with Captain Spock, returned home for Earth. 
 * Saavik was played by Kirstie Alley in Star Trek II, and by Robin Curtis in Star Trek III and IV. There are, however, a few inconsistencies present with this change of actress. Alley's eyebrows were not characteristically slanted like all other Vulcans seen to that point. Her hair has also changed from straight to curled when picked up by Curtis, although her eyebrows now have a familiar Vulcan slant. Additionally, Alley's eyes are green while Curtis has brown eyes.