I'm not sure if Abby's girlfriend is a red herring to be a spy, the way she only speaks of lying/secrets, how everyone keeps mentioning that she's french and not american etc, it is too obvious surely.
That said I don't know why anyone would target the wife of a scientist when she should keep her head down (assuming the real target would be Elodie's husband) or risk losing her phone job/worse. But the show needs a way to not lose Abby (for Charlie's homelife), and a breakdown in marriage or her getting imprisoned would make that much harder.
