Laughter Among the Trees by Suzan Palumbo

Laughter Among the Trees by Suzan Palumbo (The Dark #69, February 2021)1 opens with Ana driving to a park in Canada, during which she recalls (a) her arrival in the country as the child of West Indian immigrants, (b) her early days in school, and (c) the birth of her sister Sab. Ana then recalls a childhood family camping trip where her younger sister disappeared during the night (Sab left the tent—against Ana’s wishes—with Greg, a boy she had been playing with earlier that day). Sab was never seen again, nor was the boy—and there was no evidence he had ever been at the campsite.
The story then moves forward in time to when Ana has grown up, her father has died, and her mother is in a care home. During one of Ana’s visits to see her mother, the old woman talks about the disappearance of Sab and shows Ana a picture of a boy that looks like Greg—it materialises that Greg was a cousin of Ana’s mother who drowned back in the West Indies in 1962 when Ana’s mother wanted to go swimming in a flooded river. She tells Ana, “‘dis go haunt you here.’ You can’t outrun the past, Ana, even if it’s dead and drowned in another country.”
The story closes with Ana going back to the camp site. Then (spoiler), on the second night, a ghostly Sab appears and tells Ana to follow her. They go to a cave, where Ana finds Sab’s remains and later lies down beside her bones. The story closes with Ana feeling a dense cold, and something gripping her throat.
This is reasonably well told, but it seems to be more an autobiographical slice-of-life than a ghost story (the immigrant background, the family accounts, and the dysfunctional relationship with her sister, etc.). I’d also add that the internal logic of the haunting doesn’t really convince: I can see why Greg would kill the mother or Sab for revenge, but why would Sab lead Ana to the same fate given it was her own childhood stupidity and wilfulness that got her killed?
Finally, there are one or two sentences or word choices that could do with being changed, e.g. the very clunky first sentence:

The highway to the campground cuts through the granite Laurentian Plateau like a desiccated wound.

What’s a “Laurentian Plateau”? Do wounds become “dessicated”? Why distract your reader with this kind of thing? Wouldn’t, “The highway to the campground cuts through the plateau like an old wound” be a simpler and more apt beginning (the story is in large part about an old wound)?
** (Average). 5,950 words. Story link.

1. This was a 2022 Nebula Award finalist in the short story category. Another mystifying choice.