In this alternate world, Fluttershy and Derpy Hooves were adopted at a young age by Rainbow Dad (Dash's dad), after Fluttershy and Derpy Hooves both had bad experiences with their fathers, and their mothers were in different parts of the world. Rainbow Dad took them in as his own, and raised them along with Rainbow Dash. The three fillies were all very good friends to begin with, so it was an easy fit into this new family. It's a new series of stories that depict their hard times growing up, as well as the fun things and new experiences that they will discover.
In this one however, we go back a long ways when the family's relationship was just beginning. RD and FS are about 12-13 in this one, and it shows the dedication of one Pegasus to save her sister from an untimely and tragic death. It also shows the deep bonds and connections between the characters in this new universe of MLP, and how they fight through the rough times and the grief and pain that comes with it. I hope you enjoy, 'Snowy Days and Nights.'