The eldest was Dainty (I'm going with the name Celestia's Servant gave her in one interview), who got hitched, had dfoaughterls named Chirpy and Dipsy, and moved to Rainbow Falls at some point between "Baby Cakes" and "Trade Ya".
The youngest was a late surprise, a colt named Crackle Pop.
The middle foal, named Derpeline, married her high school sweetheart (Amethyst Star's older brother) and they had a daughter named Dinkamena. Derpy's husband died shortly after Princess Luna's return. A few years later, Derpy married Thunderlane.