Question about "A Ghost Story" (2017 film)

I finally saw A Ghost Story about a week ago, and I liked it very much. I can understand why some people didn’t think it was all that, but it worked for me. At any rate, one point I have been wondering about. (spoilers ahead)

Casey Affleck’s ghost occasionally waves from the window to a ghost in the house next door, a ghost that is deeply depressed and waiting anxiously for someone who never arrives, but has been waiting for so long that she doesn’t even remember who she’s expecting (which struck me as profoundly sad.) For whatever reason, I instinctively felt that this other ghost was female.

Fast forward to the end of the movie, and Affleck’s ghost time travels far back to the Wild West. He sees a nuclear family (mom, pop and a little girl) who are either planning on settling in that spot or just camping out. But at any rate, they are attacked and killed by Natives. The ghost sees the girl’'s deceased body laying there abandoned; then decaying; and finally her skeleton being covered up by the elements.

I don’t know why I made this deductive leap, but I thought that the dead little girl was also the depressed ghost who lived next door in modern times. I didn’t even question it, I just assumed that it was the girl’s ghost who was waiting for the other settlers to arrive and over time, she lost her memory of the facts of her life, but not her feeling of isolation and abandonment.

Anyway, I happen to be discussing this film with a friend who didn’t get that at all, and thought I must have read into it. I’m just wondering if anybody else thought that or maybe had spotted a hint or bit in the film that might suggest this? Just wondering.

I don’t think I made that connection when I saw the film, but it’s certainly a valid theory in my opinion.

Though I’d wonder if the ghost would need to be little girl sized, or perhaps if they were all killed together then they wouldn’t be searching for something like OUR ghost.