Thrudr
Thrudr is the daughter of Sif and Thor. Her name means “Strength”. There is not a lot known about Thrudr in the lore. But we do know that she is a daughter of Thor. Because of Snorri Sturlusson’s Edda. Where it lists a kenning of Thor’s as “Father of Thrudr” in the Skaldskaparmal.
There seems to be a lost story about the Giant Hrungnir and kidnapping Thrudr. This is suggested because in Bragi Baddason the Old’s Ragnarsdrapa (1). Where it calls Hrungnir “Thjofr Thrudar” (Thrudr’s Abductor).
Thrudr is listed among the Valkyries in Hollander’s the Poetic Edda pg. 60-61.
Hrist and Mist the horn shall bear me,
Skeggjold and Skogul,
But Hild and Thruth,
Hlokk and Herfjotur,
Goll and Geironul,
Randgrift and Rathgrith and Reginleif,
To the einherjar ale shall bear.
There is no proof in the lore. That Thor’s daughter Thrudr is the same Thrudr listed among the Valkyries. Listed in the Edda.
Once when Thor was away fighting giants in Jotunheim. The dwarf Alvis (All-Wise) came to Asgard. While he was there he was able to convince the Gods to let him take Thrudr as his bride.
On his way home with his new bride. Alvis was stopped by Thrudr’s father. Thor was none to happy to come home and find his daughter gone. So Thor decided to trick Alvis into a contest of knowledge. And in so doing kept Alvis up all night. Until Sunna rose in the morning trapping Alvis and turning him into stone forever.