In my MLPFIM alternate future, Pinkie and Flurry are very close and she calls her "Auntie Pinkie" sometimes. Pinkie loves her so much, she gave her a bow the same color as hers and calls Flurry her "Matching Bow Mare". They've obviously been friends for a while, but now that Flurry has come to Ponyville to start learning more about the magic of friendship, Pinkie is more than happy to help her out!