Decided to do a more refined version of this:
 
This is basically the start of a new project where the family trees of Kilala’s new NextGen are “Fused” with her old ones:
 
Story:  
Parents:  
Mothers: Twilight Sparkle, Sunset Shimmer.  
Fathers: Flash Sentry (Pony and Human).
 
Children by Parent:(From left to right):  
[Sunset & HumanFlash]: Sunray  
[Twilight & Sunset]: Sunshine  
[Twilight & PonyFlash]: Starburst, Night Light Jr.
 
From Oldest to Youngest:  
Starburst, Sunray (Born around the same time)  
Sunshine  
Night Light Jr.
 
History:
 
In the human world, Sunset and Flash had rekindled their relationship and got married a while after their graduation. Flash eventually became a Police Officer to support his family after Sunday was born, unfortunately he died in the line of duty during a bank heist. Grief-stricken, Sunset returned to Equestria with her daughter (who became an earth pony as a result). Twilight and her husband Flash allowed her to live in the castle where she began work as an assistant.
 
Flash and Twilight helped Sunset move on and the three bonded over studying magic with Twilight, sharing stories with the couple about events and adventures they’d had in both worlds, and even having a sparring sessions with Flash. As time went on Sunset grew closer to the loving couple, to the point where their friendship turned into romance, which soon escalated into “special sessions” between the three. Eventually, with a bit of “all-night convincing” for Flash (as well as Twilight going through several law books before successfully legalizing polygamous marriage), she and Flash agreed to an open relationship and welcomed Sunset into their family, and a few months later Sunshine was born.
 
Afterwards Sunset discovered she had a knack for combat magic, to the point where she decided that her talents were suited better in the Royal Guard. She joined and eventually became the second in-command under, out-ranked by Flash himself due to experience.
 
As Sunray grew older she slowly bonded with Starburst, thought needed some time to adjust to living in a new world as well as getting to know her “second father” (though a small part of her was bitter that her mother had dragged her to another world), she eventually mellowed out after Sunshine was born, and even more so when Night Light came into their lives…