Ever since she was a little filly, Scootaloo hasn't gotten to spend Hearth's Warming with anypony else. She never gets invited and she never asks to be included. Hearth's Warming is a day to spend with family and friends, and neither family nor friends seem interested in making her a part of their plans or to include her in any way.
A chance meeting with another pony on Hearth's Warming Day may give her a brighter outlook on the holiday. She doesn't want to be alone, just this once.