What is the name of movie about some people where girl finds a fairy cave and eats food supposed to be trapped there forever then her brother they escape?

The movie you're describing is "The Secret of NIMH" (1982).

Here's why:

* Fairy Cave: The film features a hidden, magical cave where the mice live, filled with strange and wondrous things.

* Food Trapped Forever: The film features a "Time Stone" that preserves food forever, meant to be a secret source of food for the mice in their underground home.

* Girl & Brother: The main characters are a young girl named Mrs. Brisby (who uses a wheelchair) and her son, Timothy.

Let me know if you have any other movie puzzles for me!