Now, I bring a small drawing where it now appears my version of the children of Rainbow Dash and Fluttershy, from the ship “FlutterDash”  
In the picture we see how the two children of Rainbow Dash and Fluttershy are taking a friendly and “relaxing” flying with their both twin siblings; Fearful Wings and Vanilla Wake, where Rainbow and her daughter Vanilla instead of taking a relaxing ride, just compete to see the more fast of the two, while apparently their speed trails that their velocity leaves behind, reel Flutterhy and Fearful.  
I haven’t yet presented their children in PNG format with their personalities and names, I’ll do it later, but I will give some details here.
 
The son from behind; “Fearful Wings” is the one that came out more to his mother Fluttershy, but instead of being shy, he’s a bit more fearful and insecure at the time of act.
 
The daughter flying with Rainbow; “Vanilla Wake”, is determined, rude and adventurer just like her mother Rainbow Dash, that’s why she never doubts accepting a flying contest.