What if Carrie is to Laura what Dougie was to Coop? Which would make this final scene one of Laura waking up? And if this were the case, why would Laura have a Dougie? In this episode 18 world of Twin Peaks, if there is a Dougie-Laura, there must be a Mr C-Laura who created her...?
And why would there be a Mr C version of Laura? If Laura wasn't dead, then Coop never went to Twin Peaks. And if Coop never came to Twin Peaks, then he was never possessed by BOB. So where did BOB go? You remember Leland's dying confession? That BOB tried to take Laura but she was too strong...? For a time, perhaps... My theory? Laura is BOB and Carrie is her Dougie.
No idea where Judy and Sarah fit in with this mind...
Answering one's own post is the first sign of madness: the electricity at the end, with the house going black, further suggests Carrie waking up from her Dougie state...
I don't think the scream is her remembering. It is her snapping back into Laura.
"We all go a little mad sometimes."
Especially around here.