Preteen (maybe 13 y/o) girl lives in New York (most likely Greenwich village) with her single mother. They are about to lose their apartment or an apartment building is about to be torn down. She and her best friend, who is a POC, try and find a special artifact in the building before it is torn down or save the building from being torn down at all. I remember that a tree is growing in the foundation of the building. This girl and her mother sometimes ate egg sandwiches whenever they were upset. The girl and her best friend liked to skateboard.