Why does Esperanza want to eat lunch at school in "A Rice Sandwich"?

She sees the kids who eat lunch at school as "special."

She doesn't get along with her mother, so she doesn't want to eat lunch with
her.

Nenny, Carlos, and Kiki eat lunch at home, and she is tired of fighting with them.

Her house is so far from the school that she is late returning to class after lunch
every day.