I have some questions. How do I fit Thor's kids into the timeline?? How do the ages work in Asgard - I know the average Asgardian has a lifespan of several thousand years, but Thor, Loki and the Warriors Three act more like immature adults than centuries old Gods. Can you help?
There is no set timeline when it comes to what we consider Norse mythology– that is, the stories contained within the Eddas. And frankly my knowledge of Marvel timelines, retcons, and AUs is not what it used to be, so I can only speak to the eddaic side if things. Keep in mind that the Warriors Three don´t have an analog in the Norse mythos, so I can´t speak to what drives their behavior. But I think it is in many ways better to think of the Æsir and all their shenanigans outside the purview of structured time– they are, after all, the powers and pillars of the universe. That they should be beholden to a linear timeline does not quite fit. Take, for instance, Ragnarök. You can look at it as an event of the past: the gods are dead, Christ has come, we are living in the new golden age. But in many ways, you can look at Ragnarök like… well, Galadriel and her mirror in The Fellowship of the Ring, to bring in another nerdy metaphor. Ragnarök and all the events and existences of the gods, are things that are, were, and have not yet come to pass. If linear time is an illusion of creation, then it stands to reason that individuals do not mature in a linear fashion. Indeed many of the Æsir seem immature and hotheaded– perhaps it is because time does not affect them in the same way it affects us.
The gods come from the Old Norse neuter plural noun, góð, which long ago referred to a plurality of entities. These deities began as góð, as the other, whoever is out there and is responsible for the drought, for las year´s good harvest, for my cheating wife, etc. Them. Over time (our time, that is) this omnipotent they began to split off into individual deities: Thor is responsible for rain and the working man, Freyr helps with fertility in the fields and in the home, Freyja´s knowledge of seiðr encouraged my wife to cheat, etc.
That being said, obviously there are handful of stories in the Eddas which clearly map out sequences of events, or allude to things which must have occurred at a given time. The gods have magic apples to eat, provided by Iðunn, which keep them from aging, so– in some respect– time does affect them (if we take Snorri´s word for it). Whether it is linear or not, time does influence the events in the Eddas. In Lokasenna Loki brags about killing Baldr, therefore Baldr must be dead at this point, if we approach this with a linear perspective. When Thor defeats the Jötunn Hrungnir, the lesser Jötunn Mökkurkalfi fights Thjálfi. For Thjálfi to be there in Thor´s service, he must already have been picked up by Thor and Loki on their trip to Útgarð. So, if we want to do so, there are things that we can piece together in a linear framework.
Now, about the kids: that same tale of Thor vs. Hrungnir also features Thor´s son Magni, who was said to lift Hrungnir off of Thor with great ease (for which Thor rewarded him with Hrungnir´s pretty horse, and Oðinn was pissy bc he wanted the horse, but I digress). Depending on which manuscript of Snorra Edda you consult, Magni is either three winters old, or three nights old. Either way, he is not described as a fully sized adult, which is of interest because Freyr is the only other Áss who we know, for certain, had a childhood (he was give Álfaheimr as a “teething gift”). We have no clue what the early life of most of these góð– Æsir, Vanir, and Jötnar alike– entailed, or even if they had an early life, and did not simply spring into being the first time a human being thought of them as an individual, outside of the big polytheistic whole. Freyr and Freyja are supposedly twins, so we should be able to say that Freyja also had a childhood, but we can´t. Too many of the Æsir– Borr, Bestla, Oðinn, Vili, Vé, Kvasir, etc.– were created as adults or literally, in the case of most of the folks listed above, sprang up out of holes in the ground. So in the case of the sort of second-generation Æsir, for lack of a better term– Thruðr, Görsimi, Váli x2, Forseti, Moði, Nári, etc.– we cannot definitively say a) if they were ever children, or b) where most of them fit into a linear timeline. I mean, this is a mythological corpus wherein cows can birth grown men by licking ice, a Jötunn can procreate by rubbing his knees together, and a Töll-kona can give birth to a snake big enough to give the entire earth a hug: we cannot take childhood as a fact of certainty.
So, the short answer to your question is: idk about how it works in the marvel 616 these days, but in the Eddas we cannot affirmatively age Thor´s kids in terms of when they came into being or when they cease(d) to be, the gods are timeless– they may age and can die, but none are on record as withering away in senility– and many of their actions which we might call immature (ie. Thor getting pissed at everything, Loki killing Fimafeng for literally no reason) are the product of a long history of oral storytelling, varying cultural perceptions, wavering favor between each of the gods (ie: Thor more popular in Iceland, Oðinn in Norway, Freyr in Sweden) and most importantly: that all actions and peoples within the Eddas are presented ages after the fact by Christians so. ¯\_(ツ)_/¯ I would put together a timeline for you myself, but I tried and it sucked? It sucked so hard to try and do? maybe over christmas break or something. Sorry!