Poor Sunset….
Headcanon: Sunset has a terrible time trying to have foals. She managed to have one kiddo, but the pregnancy was nothing short of a nightmare. Hence why the second attempt she turned to a surrogate mother instead.
Find your happy place, Flash.
Human!Flash was finally given a second chance by Sunset and it worked out fairly well. They moved to the Equestrian side of the portal for a fresh new start and so Sunset could be closer to her long-missed baby brother Sunburst. They eventually realized they just weren’t meant for one another and ended up having a divorce and are on decent(?) terms. Flash remained in the Pony World to keep in touch with his son and eventually remarries to Spitfire. So technically Solar Flare is half…..human. Yep.
Not my best work but I hope you still like it~