It took a while but I eventually got these three done. Shining Armor/Cadance kids, Cricket Medley, Lirico (or Lyric) andPearlSabre Dance.
Cricket Medley is a timid sweetheart with a stutter that only seems to go away when she sings. Like Kite Runner she seems to have the rare pegasus gene that allows her to absorb the energy of lightning strikes but instead of giving her a speed boost it makes her glow. Like a firefly. I'm taking a cue from this super cool pic >>1209317 by asluc96 where Firefly is their child. But I decided to be "different" and use Medley instead. I already have a Firefly like Next Gen in the form of Kite Runner so in essence Cricket is her "Medley"/ voice of reason/best friend".
Lyric is a charming, relaxed, laid-back jokester type. I personify him very close to how I imagine Cadence's father would have been like. I have this weird thing with reincarnation in mlp. It's how I justify (in some but not all cases) using ponies I love from previous generations of mlp in my headcanons. I think of him as a bard and traveler. His voice can inspire, literally. Yes a magical singing voice, and it's versatile in many different circumstances. He can inspire his friends to strive for the impossible or confuse a group of enemies with the right tune.
Sabre Dance, my initial idea with him is that even when he grows up he'll be adorable as heck. In my mind he's supposed to be Unico but deadly. Somewhere along the way he got that swept back mane that is very iconic of a certain crystal gem (I wasn't trying for that, it was coincidental) Add in his mad proficiency with pointed objects and I guess I did unconsciously make him a little Pearl-ish. Sabre is quick and light on his hooves but he's not anal retentive and probably a lot less salty. He's overflowing with this oddly polite self confidence and a strong sense of honor and fair play…most of the time. He will also drop anything for tea time.