Why is the girl embarrassed ?

Georgina is embarrassed because her father walked out on the family, leaving her mother, her brother (Toby), and herself to get evicted. With nowhere to go, they lived in the family car. Georgina wants to keep her best friend, Luanne, from finding out her circumstances.

Georgina felt embarrassed, because ever since her Dad left, when her family got kicked out of their apartment and when they lived in a car in the first place, Georgina doesn't want anybody to know that she's homeless and her family lives in a car. Especially her School Bully.

I hope this helps! :)