Here's how I see it:Natalie doesn't win the next IC and is voted out 3-1.
If we have a F3: It'll be a race between Cirie, who played the better game, and Amanda, who is better-liked. Parvati is on the outside due to too many jury enemies. If we end up with a F3, I think Cirie should win but Amanda will win.
If we have a F2: Cirie will lose the next IC because she's completely useless in challenges. If Amanda wins, she takes Parvati to F2 because a) they've been friends/allies throughout, and b) Parvati is an easier F2 opponent. If Parvati wins, she takes Amanda to F2 because they've been friends/allies throughout and she has less loyalty to Cirie. Either way the F2 is Parvati and Amanda. And I think Amanda wins this matchup hands-down.