Wonder Lesson Plan

What does Auggie's mom mean when she says "I guess the apple doesn't fall far from the tree" (67)? What is she trying to say about Julian or Julian's mom?

For his birthday on October 10th, Auggie wants to have a bigger birthday party than usual at a bowling alley. When Auggie and his mom are discussing who to invite, she asks if he really wants to invite Julian since he'd been rude to Auggie earlier in the year. Auggie is annoyed that his mom is still holding to that grudge, and she admits she should let it go. They end up inviting everyone in Auggie's class, as well as Summer. Many people RSVP to say that they can't make it, but Julian's mom is the only one who doesn't...