Read the excerpt from "I'm Not Thirteen Yet" by Amy Bernstein.Lynette started bringing new thirteen-year-old friends to our lunch table. Then Lynette and these new girls began holding thirteen-year-old clubs after school. Obviously they were far more mature with the word "teen" attached to their age. It wouldn't be long before there was tape down the middle of the cafeteria, dividing it in two. If you weren't thirteen, you dared not enter the thirteen-year-old side. If you tried, the lip-gloss army would hurl you back.Gradually, Lynette stopped inviting me over after school. One day, on my way into the girls' bathroom, I overheard Lynette and Shelley Abrams discussing their after-school plans at Dale's Ice Cream.