I have decided to give 당신 all Moon Dust's back story so enjoy and comment!
Moon Dust was born on Hearths Warming Eve. Her father was a pegasus named 나무, 트리 Whisper. Nopony knew who her mother was. Moon Dust was delivered onto her father's house the night she was born 의해 Princess Luna.
Luna said she found Moon Dust in the snow 의해 the 성 with a note telling the princesses he was her father. Luna said she sensed great power from this filly. 나무, 트리 Whisper asked her to name the filly because naming the filly was not his job.
Moon Dust was named Moon Snowy Dust Moon Dust for short. 나무, 트리 Whisper raised Moon Dust until another filly with a 무지개, 레인 보우 mane was delivered to his house with a name and note saying she was named 무지개, 레인 보우 Wing. 의해 then Moon Dust was 2.
When Moon Dust was 10 she was accepted to Celestia's School for gifted 유니콘 and when she turned 12 she was made Luna's apprentice.
So that is most of Moon Dust's back story