From Deviantart:  
Inquiring minds have wanted to know if Adagio and Sunset are going to have any children in Junior Gala. The answer is of course not. Horses cannot produce fish, nor vice versa. Any first-year biology major worth their salt knows that.
 
But I never said Adagio and Sunset wouldn’t adopt.
 
Here now comes Dal Segno Shine, or Snowshine for short. She was born crippled and sick from a putrid egg of a dying clutch, and by all accounts Adagio and her sisters should have abandoned the scene as soon as they stumbled upon it. At best, Adagio could have slaughtered the broken pup to put it out of its misery. To this day, Adagio can’t explain why she defied her perfectly sensible instincts and retrieved the wretched creature, bringing it back to Sunset for a heal-and-nurture-fest that would quickly turn into a permanent gig.
 
Adagio also can’t explain why she grew to enjoy said gig so genuinely. Nor can her sisters, sensible sirens to their own credit, explain why they’ve warmed up to the whole aunt concept. Hippocampi don’t have aunts OR mothers who actively raise their young…then again, Hippocampi eat their sisters upon hatching, and they sure as heck don’t hang with pretty little unicorns.
 
Who knew?
 
mlp:fim = Hasbro/Faust  
Snowshine is Liz’s brainchild. Honestly, if it pertains to JG Hippocampi, you can be certain that Liz’s hoofprints are all over that sucker. Your pal Frog just operates the pencil in these situations.