Convinced I made this movie up

Hello! I really hope someone also remembers this movie and doesn't think I'm crazy, I watched it as a kid.

Fuzzy plot: There are two kids, I believe siblings, they live in a house surrounded by forest and or shrubbery. I believe the father had died in an accident and the mother was left taking care of them. I think it was the sister who disappeared first, she would go and come back and tell her brother and then convinced the brother to follow her. This is where my memory fails me.

There are three witches/magical women who help these kids when something starts to go wrong in the other place. I remember a large metal building in the middle of the town and a flock of people are heading to it. In a different scene, one of the siblings is tricked by the main antagonist in the movie, one of then is trapped in a room with the floor having the same pattern as a checkerboard. One of the siblings saves the other by telling him it isn't real and that everything the villian is telling them is a lie.

I KNOW this movie is out there somewhere and if someone can help me, I would be forever grateful.

EDIT: I'm 19, born 2004.