Oooh! I have a whole list of this.

Anya Erdene is the firstborn and actually has the soul of Hythlodaeus in her following Ultima Thule. When Tso made it back onto the Ragnarok, Hyth basically looked at Hades in the aetherial sea and was like '....I can't let Azem suffer like that' with like that equalling losing a baby she wasn't even aware of. Hades just like, eyerolling bc again Azem be doing the most but he also understands bc he knows how Tso is and would hate to wish the fate of losing a child on anyone after having been through it himself. So the mischievous curiosity Hyth has deff transfers into Anya's personality as well, and she is the gd light in their life.

Zakari Andranik is the firstborn son, and I'd say he's probably born 2 years after Anya, which is also dependent upon once we see what 7.x and 8.x are like, sometime in between there. He's magickally adept like his mother and follows in her steps to become a thaumaturge.

The younger son, Ahsan Cathal, is hellbent on being an adventurer and deff takes after Thancred, damn near a mini-him but just with Xaela features. May take after him in the rogue department, but he always loved hearing the stories growing up of the adventures his parents and aunts and uncles would get into.

Carys Gerel, the baby daughter, is very rambunctious, can't ever sit still. Very, very attached to Ryne and a natural healer. While they can't say for certain, she's got a bit too much of Minfilia's personality for them to just brush off as coincidence. I've yet to determine if Carys and Ahsan are actual twins or 'Irish twins' but they are v close in age, if not the same age. They'd be maybe 3-5 years younger than Zakari.