Aimee Anne Gillespie has been friends with Madison ever since they were born. She is thin and has blonde wavy hair, and loves to dance ballet, stating that she is planning on being a professional ballerina when she grows up. She practices daily, sometimes even going before school to practice. Aimee is known to be blunt and sometimes mean, but she is usually quick to apologize afterwords. Aimee loves to gossip, but would never betray her friends. She is also very afraid of water: when they were little, she fell in the water and never came up until a minute after. Aimee was diagnosed with anorexia in the book, Picture Perfect after she fainted and is battling her constant thinking she is fat. Aimee is a committed vegetarian and is always on diets, constantly believing she is overweight.
Aimee has been friends with Madison ever since they were born. Madison finds her sometimes blunt and a bit mean, but Aimee is quick to apologize afterwards. Aimee loves to gossip, but she wouldn't hurt her friends, and Madison knows that. When she started taking a like to Ben Buckley, Madison was a bit surprised but later respected Aimee's choice. When Aimee became anorexic, Madison was worried for her health along with Fiona and often asked if she was okay.
Fiona and Aimee became friends shortly after Fiona moved to Far Hills. The three BFFs, including Madison, became very close. They went shopping, had sleepovers, Madison and Fiona would go to Aimee's dance recitals, Aimee and Madison would go to Fiona's soccer games. When Aimee became anorexic, Fiona witnessed her fainting, and went to go get a teacher. She was worried for Aimee, and often told her she should eat.