It was known that current Yuna and her mother is Yuzare's descendant, but there wasn't any clue who was her husband/mate. In Ultraman Tiga, we can possibly guess that Tiga himself was her husband. *It is kinda implied in Camilla's dialogue and captain Iruma,Daigo,and Keigo are possibly their descendants. But in Trigger it seems that Yuzare never had any chance to pass her genes she just sacrificed herself in ep.12. Sure she might have her unseen children somewhere off screen, but it seems not likely because it looks like every single humanity is wiped out. Plus she doesn't seem to be in any relationship with Trigger.
I know a fact that Daigo is both Tiga & Yuzare's descendant and Tiga's reincarnation. (maybe the trope I'm my own grandpa would be applied here) But Kengo is only just a reincarnation (or self) of Trigger, not a descendant. He was literally born right out of petrified body of Trigger and not born like a normal human being nothing related to Yuzare or ancient people.
Well it doesn't have to be exactly the same but I'm very curious about this and pls correct me if I'm wrong.