Ever since she was a little filly, Limestone Pie was a very ambitious, hardworking pony. Even back then, she took pride in a lot of things: her work, her hobbies, and her role as the eldest sister of the Pie Family. But when Pinkie Pie exclaimed on how great Maud Pie was when they were making rock candy necklaces together, Limestone began to fret over losing her status as "big sister" forever. So in order to prove her worth, she decided to join her sisters in their 2nd Annual Rock-Candy-Necklace-athon, and she brought along the one pony who can help her reclaim that title... her baby sister, Marble Pie.