RandomTalks here with a short review!
While I was reading the story, I was very confused as I thought it read very similar to something I have read before. The characters and even the situations felt very familiar and it took me a moment but I finally made the connection with your other story named Lydia's Story.
Once I had placed it, the experience of reading this story became somewhat different. I was viewing the same story from a different lens and it made me all the more attached to the characters and concerned about what I knew was going to happen to them.
I loved how the introduction reads more like a prologue that engages our curiosity at once and pulls us into the story and into the lives of our main characters. I enjoyed the fast-paced narration which was directed almost entirely by dialogues. It presents us with an interesting situation as our entire perception of the characters depends on the interactions between each other. So here, I would suggest giving each character a distinct voice so that their personality shows through their dialogues.
For example, here:
“Of course it can’t! Why would anyone trip on themselves while skipping? You’re a dumb sister-“
This exchange between the siblings was going very steadily and their reactions were very typical of the relationship we usually get to see between brothers and sisters. Elsa calling him mean made me smile but then the entire interaction ended suddenly with Michael responding with a single word, "okay." This response felt a little unnatural to me (in line with the conversation at hand), unless you were trying to reflect Michael's character through this. He does feel like someone who would avoid confrontation unless he absolutely no other option.
I also liked the extra insight we got into Michael's life and the different take on the ending. The ending of Lydia's Story still left the question of their survival unclear, but here we are told that they did not make it. I do feel that you could have been a little less direct about their deaths, so that it could have left a deeper emotional impact on the readers.
Keep writing and have a great day!