I’ve seen a couple artists do this before and I really like the idea soooo TwiSet with Cozy Glow as their adopted daughter!

the thing about this Sunset, though, is that this isn’t the sunset from the show, this is Sunset Shimmer’s human counterpart. Considering how interested Sunset 1 (the one from equestria) was in going to the human world, who’s to say Sunset 2 wouldn’t feel the same? I mean, a world where all kinds of magic would be at her hands/hooves? I can definitely see Sunset wanting that. I can also see Sunset 1 trying to convince Sunset 2 to go to this other world so that there aren’t 2 sunset shimmers around to confuse things. And so they switched places… kind of. Obviously Sunset 2 couldn’t be exactly like Sunset 1 and had to hide from any pony that could know her other self. Of course, eventually somepony had to notice, and one thing led to another and eventually it got Princess Twilight’s attention. After lots of explaining, Twilight decided to let Sunset 2 stay in Equestria, but decided to keep a close eye on her, just in case she had plans similar to Sunset 1 at first. Anyway, “keeping a close eye on her” turned into long talks about magic and the universe, activities together, talking to each other about whats troubling them, spending all their time together… you know, just normal things… just to keep an eye on her. Everybody around them noticed their feelings for each other before they did, but once Twilight and Sunset could admit their feelings for each other they moved really quick. Before long they were married. A few years later, Twilight was making a plan to release the three big villains from stone, and found places for Tirek and Chrysalis, but struggled to find a place for Cozy Glow. Twilight had hoped to find a loving family to adopt her, but nopony really wants a kid that tried to take over the world multiple times. Even Shining Armor and Cadence said no when Twilight asked, but Cadence suggested Twilight and Sunset take her in. Twilight talked it over with Sunset, and after lots of arguments and going back and forth, they decided to take her in. It doesn’t necessarily mean Cozy wants her sworn enemy as her mother, but maybe eventually she’ll warm up to it