The character was actually on Star Trek: Voyager. Her name was "7 of 9" and she's was played by Jerri Ryan.

Seven of Nine (full Borg designation: Seven of Nine, Tertiary Adjunct of Unimatrix 01) was a Human female who was a former Borg drone. She was assimilated by the Borg in 2356 at age six, along with her parents, but was liberated by the crew of the USS Voyager in 2374. She joined the crew and returned to the Alpha Quadrant with the starship in 2378.

Indeed seven of nine was attractive:

Yeah, you're all wrong.. her name was Betty White and she was part of an elite team of space ninja assasins called "Golden Grrrrls." She was their knife-throwing expert. She also had a whirlwind romance with Picard one summer in France when they were growing up but it ended when Picard left for starfleet academy. She later was given the codename: Nine of Seven, because their comanding officer was dyslexic, but hey, isn't who? Anyway, Long story short, she turned out to be Vader's daughter and after a long hard-won battle she tossed the ring into the fiery pits of Mordor and saved the Universe for all robot-kind. Atl east, that's the way I heard it.

7 of 9