Hmm probably try and just leave her.
Who knows maybe they find a cure someday and they can heal her. If you can safely escape, then I see no reason to kill a person who "could" be saved.
I wouldn't lock her up in a barn or a room or something and watch over her. I would freakin leave the city or even the state so I never have to worry about colliding with her again. Then hope that someday there is a cure and that she is curable and still alive when that day comes.







