Siobhan Stocks-Lyons , 12 , and her parents , Tim Lyons and Martha Stocks-Lyons , came because they wanted Siobhan to have more serious training than she can get in Glen Cove , N.Y. Krystal Mackie , also 12 , skipped her first day of seventh grade at Mark Twain Junior High in Coney Island , Brooklyn , because she wants to become a ballerina .