Ok, another question! Who do you consider Módi's mother? Járnsáxa, given his alliteration and closeness to Mágni? Sif, given Sif and Thor are said to have a son named Hlóridi in an ehumerized account but Hlóridi is a byname of Thor? Another woman entirely? Or some Jötun-style type of reproduction since all of Thor's children are aspects of him?
Also: could you ramble a bit on Thor's children (Ullr, Thjalfi and Röskva included)?
Personally, I consider Móði’s mother is Sif, despite the identity of his mom in the myths never directly being stated in the surviving sources, which has led to speculation.
One strong candidate besides Sif is the jötunn Járnsaxa, who is explicitly named as the mother of Mágni, Thor’s other son. Since Móði and Mágni are often mentioned together, particularly in surviving Ragnarök and inheriting Mjölnir it makes sense to assume they share the same mother. Their names Móði meaning “Wrath” and Mágni meaning “Might” also suggest some sort of pairing, reinforcing the idea that they could be twin-like or full siblings.
Thor himself is a product of such intermingling, with jötunn ancestry through his mother. So, having his sons follow that same lineage creates a consistent pattern as most of the Æsir has children with jötunn women.
Now, the theory that Sif is Móði’s mother, this actually comes from the Skjöldunga saga, a later euhemerized source in which Thor and Sif have a son named Hlóridi. Hlóridi, however, is a known byname of Thor himself, creating some confusion. Since Sif is Thor’s canonical wife in the mythos, it would make narrative sense for her to be the mother of at least one of his children, like Thrudr.
A third possibility is that Móði’s mother is simply unknown, and she wasn’t preserved or prioritized. This wouldn’t be unusual. Norse myth is fragmentary, much of it preserved through oral tradition, and many figures’ parentage or full stories were likely lost before being written down. That's at least a blank canvas for someone to insert an original character, how fun!
As for Ullr, Thjalfi and Röskva I don't know what you'd like for me to ramble about. But I'll glady tell you how i personally see them and their relationships with Thor! I honestly don't know who Ullr’s father would be, I've always just left it to stay unknown as that tends to be a recurring theme. I'd imagine he sees Thor as his father though, and they're close in some way.
For the human siblings, they're still treated as servants but sorta adopted. Thor, Sif and their kids most definitely see them as family but I'd like to imagine they maybe marry into the family? XD
Hear me out, Thor would probably trust someone who has helped maintain his house for years to marry his daughter or son than a.. certain poor dwarf named Alvíss!
I think Thjalfi and Magni would make a cute couple. As for Roskva..? I haven't decided who she ends up with yet!