In Guðrúnarkviða I, Gjúki's second daughter is named Gullrönd while in Skáldskaparmál she is called Guðný. Gjúki's son by another woman is Gutþormr. With the death of his grandsons Erpr, Sörli and Hamðir the line of Gjúki came to an end.
Gunnarr ok Högni, Gjúka arfar, ok it sama Guðrún, systir þeira; eigi var Gutþormr Gjúka ættar, þó var hann bróðir beggja þeira; allt er þat ætt þín, Óttarr heimski.
Gunnar and Hogni, the heirs of Gjuki, And Guthrun as well, who their sister was; But Gotthorm was not of Gjuki's race, Although the brother of both he was: And all are thy kinsmen, Ottar, thou fool!
The Saga of the Volsungs, Part 4 (Betrayals)
The Saga of the Volsungs, Part 5 (Die like a drengr)