I'm trying to understand the family structure of Odin's family. So what is it?
The simplest reading would have it seem that Odin had a son by Jorth named Thor, and a son by Frigg named Balder, and a and a son by Gritr named Vitarr and a son by Rindr named Vali.
Using the Skaldskaparmal that list becomes enlarged, though there has been many criticisms that it was a late addition by Christian priests to position Odin as god of all other gods and thus, "there be one god, goy, and we know the most about him, goy".
The list of the supposed "Odin's sons":
Baldr and Meili
Víðarr and Nepr
Váli, Áli
Thor and Hildólfr
Hermóðr, Sigi
Skjöldr, Yngvi-Freyr and Ítreksjóð
Heimdallr, Sæmingr
Höðr and Bragi
One that stands out immediately to me as a corruption and a mistake is Yngvi-Freyr since Frey is a Van and could no way be born from an Aesir only through the race of Vanir.
Placing a name under each supposed mother:
Frigg: Baldr, Hermóðr (takes up Frigg's request to ride to Helheim first called brother of Balder), Höðr (understood as twin brother of Balder and killer), Bragi (condoned by Frigga for only using words against an enemy in a mother's scolding way)
Jorth: Meili (only Thor calls him his brother), Thor
Gritr: Víðarr
Rindr: Váli
<Mother Unknown>: Nepr (father of Nanna, Nanna was the wife of Balder, making Balder and Nanna's son Forseti an incest which Odin himself is much against), Áli, Hildólfr, Sigi (Odin's supposed "third son" and one of the few known important deities for the Franks), Skjöldr (a supposed god from the land of Scythia according to the Skjöldunga saga, only known as a boy in a boat without any oars), Yngvi-Freyr (maintaining just Frey and not possible to be a son of Odin), Ítreksjóð, Heimdallr (attested as having nine mothers, usually understood as being born in all the Nine Worlds at the same time, as a sort of guide/scout/messenger), Sæmingr
Is Frigg and Jorth the same goddess? Both have a connection to the Earth, with Frigg's more Germanic name being Fulla or Hulda comes close for another name of Jorth being Hlotyn. Also there are Latin inscriptions in the Rhineland to Hludana made during Roman conquest showing a seated goddess which Fricka is shown often as. Grimm said he couldn't find a way that Hlóðyn wasn't Hludana.
So if Frigg and Jord are the same that leaves two giantness giving birth to Víðarr and Váli. I would guess Váli is the latest son Odin has had but I can't place a time when Víðarr was born and for what reason.
Interestingly enough Víðarr and Váli have names very similar to the more ancient names of Odin and his brothers. We know much about the son of Burr named Woten but Vili and Vé much less. Either Vili or Vé could have had done with an Aesir talked about in the medieval times but more recently not as much known as Methothin/Mitothin. There was another Aesir of this time Irminsul/Irmin attested in the 12th century Kaiserchronik, where idols of the Aesir still stood. Both in their medieval times are depicted like an "Odinic" figure but have different traits from Woden himself. Were these two the brothers of Odin?