Lucy

At the start of Earth Taken 3 you escape from an Alien Base. Along the way you locate a girl in a tank- you have 2 choices- to leave her or free her. Leaving her allows her to still come along later somehow, except she has no advanced personal story.

As a male character, it is suggested you may have some sort of sexual attraction to Lucy.

Freeing her allows the story to progress normally with her in it.