The marriage of Lulach and Brina was arranged, however the two eventually grew fond of each other despite their difference in political views. It simply wasn't spoken of.
Caerell was killed during the story The Shattered Web
Lulach became an invalid during the quakes in the story Scorched Earth because his inability to fulfill his responsibilities, the title of Lord was passed to Daegan.
Brina found out she was pregnant with Branwen towards the end of Hell's Fire
Lulach died a year after Branwen was born.
Daegan
Married
Kerensa Davan
Davan
Briara
Dane
Ciara
Notes
Daegan is the current Lord of the Thorneton.
Daegan was a page in Kerensa's father's Castle so the two grew up together.
Upon learning that Kerensa was kidnapped and was to marry Dane Amherst, a man that Kerensa despised, he invaded Amherst castle, took Kerensa and the couple went to Wyvern where they were married.