<PERSON> from BTTF left behind
In BTTF 2 after <PERSON> and <PERSON> come back from the future (to 1985) where <PERSON> has already gone to 1955 and changed 1985, they stop off at what they think is <PERSON>'s house and leave her on the porch swing at night. Of course, as that timeline is now changed to <PERSON>'s Paradise, that is not her house presumably.
At this point the remaining story of BTTF 2-3 progresses. BTTF 3 ends with <PERSON> coming back to 1985 and arriving at <PERSON>'s porch where she is still in the same place, waiting to be awoken.
My confusion is this: She was left in the timeline while it changed from Biff's Paradise(BsP) to the "regular" timeline. Considering if the movie uses either the distinct multiverse theory, or one in which there is a single timeline which can be and does alter to accommodate changes within itself, there must be two possibilities:
Multiverse- <PERSON> is left on the porch in the BsP timeline and when <PERSON> and <PERSON> leave to change the past in order to return back to their "normal" timeline, she is left in the BsP timeline and should NOT be in the "normal" timeline, as she was taken OUT of it along with them WITHOUT being brought back to the "normal" timeline by the DeLorean. 663
If you can imagine two lines where line 1 is the "regular" timeline and line 2 is BsP timeline. If <PERSON> was pulled from L1 to the future and set into L2, when <PERSON> and <PERSON> go back to change the past and return to 1985 it is the L1 1985 where <PERSON> should not be in.
Single, changing timeline- <PERSON> is left on the porch in BsP, but when the past is changed, her and everything in that timeline are changed back to the "normal" timeline. However, <PERSON> and <PERSON> were never in the "regular" timeline to put her on that porch in the first place. It is my opinion that if this is the movie's preferred time-theory, she should be going about her life as everyone else is after the timeline changes.
I know this whole topic is very confusing and hard to straighten out, but my final question is which theory seems to fit best, or is there another one to better address <PERSON>'s fate? 663