What is Auggie's nickname for his sister in the novel, Unlikely Animals?

Giant Grouper is Auggies nickname for his sister and represents the person that others see when they look at Emma. She has always believed that the acronym GG stands for Golden Girl, and that he uses it sarcastically because he is embittered about their disparate lots in life. When brother and sister have a heart to heart conversation, he reveals that it means Giant Grouper, or a fish that is too big and too good for the small town pond of Everton. Emma must come to terms with the fact that her closest family and friends view her as pretentious and selfish.