What's the Name of That Book??? discussion

The protagonist is a teenage girl who’s struggling to fit in at her school. She doesn’t have very many friends and is considered weird.
Her parents run an ice cream parlor/truck. She works there, sometimes. The truck has her little brothers face painted on it, because he was their mascot. She likes the ice cream business.
Then, her three year old brother dies in his sleep from a brain tumor. The whole town mourns. They paint over his face on the truck, but it was a thin white coat of paint and you can still see his little smile. The main characters mom won’t let them change the little boys room, so it’s a perfect shrine to him, except for the urn on the shelf above his bed.
I think the little boys name might’ve been Charlie?

See You at Harry's by Jo Knowles