In original LD Fawn's storyline brings you to upper new ark, and her line wasn't even finished then. I remenber Indivi mentioned maps coming to LD+ next are military base and desert town. I think you'll have to wait a bit longer.
Fawn's route brings you to upper new ark, which leads you to the answer about your mysterious past...So yes, her storyline definitely weighs more than Linlin's or Sammy's. Though it might change in LD+. Wait and see I guess.
