giving a little context, they had 2 children, a male (light mane) and a female (blue mane) both have both female and male genitalia( they don't have a name yet )
The first to be born was the male, but since she is an earth pony he was soon discarded by Sombra.
The youngest came soon after, having an aptitude for magic, and having more physical strength than her brother, the perfect heir to his empire in Sombra vision.
the two also have a bastard sister who is a servant at the castle.
twilight made a peace agreement between the kingdoms to avoid an unnecessary war. She acts as a diplomat and she often visits her niece Flurry heart
Sombra used Flurry Heart's influence to convince the Crystal Folk that she chose him as the new ruler of the empire.