[Rey sighs. Even when she thinks she isn't using complex vocabulary, she remembers who she's talking to. Not because of Firo's intelligence, but her jargon would probably fly over the heads of a lot of people from the time he's from.]

Fiona was a synthetic created to look like-human. However, upon her creation she'd developed an unstable nature that made her a volatile... well, a risk. To others and to herself. So the only logical course of action was to kill her program.

My mother tried to stop this from happening the first time. Fiona escaped, but the effort ended up costing many lives.

She was found after murdering the researcher who had... um, taken her out the first time.

[Judging by the dream, she hopes that Firo can put two and two together without her having to explain the details.]

Anyway, she was scheduled to be executed after that. Because it wasn't worth wasting the effort on damaged goods.