Caring, Protective, Intelligent, Slightly NaiveHistory:
Sarah grew up with her mother, her father having died before she was born. She went to an all-girls school, and then shortly thereafter, an all-girls college. Unlike many of the girls she grew up around, and who were her friends, she was not a rule-breaker, or a rebel. She very rarely, if ever, snuck out in the night, and never developed any real relationships with men. She had a casual girlfriend in college, but it ended with an amicable break up. Her life was, stable.
Sarah found an intern position at a film production company, and ended up learning a wide variety of otherwise nearly useless skills. She'd finally been put in a full-time position at the company when the population suddenly disappeared. Awestruck by the situation, she found the only other person in the city, or rather they found each-other. With no way of finding out what had happened, or if anyone who had disappeared even still existed...somewhere, they focused on survival.