Hello guys I’m looking for a book I read 5 years ago and i dont remember the name this is the story if anyone knows the name please tell me

[Ayda]

The story is about two very close friends, two girls, who go on a summer vacation with their families. One of the girls visits her friend’s apartment, and when she tries to leave, she gets into an old, seemingly broken elevator. The next time she visits her friend, she notices that both her friend and her friend’s mother are depressed. She later realizes that by getting into that elevator, she traveled to an alternate reality where her friend’s little sister had died (the girl was supposed to fall off a horse and die), and this event caused the depression in her friend and her mother.

The main girl tries to warn her friend in order to prevent her little sister from falling off the horse, but no one listens to her. Eventually, the little sister does fall, but because of the main girl’s warning, her friend’s father (who is a doctor) saves her, and she is taken to the hospital.

In the alternate reality, the main girl describes her friend’s house as having once smelled of perfume, freshness, and light, but now it feels dark, and there is no longer that smell of perfume or freshness — everything is sad and gloomy.