This is crack spawned of conversations with Nemi, the muse of crack, and written as a birthday gift.
There are many more scenes in the 'verse that were discussed, but this is what got written up. There may or may not be more written.
This party was a riot.
Yeah, at first she'd been all, "So, this is what you do for fun in the middle of no and where?" But then hey, big sweaty guys. She could dig this.
The thing with the car was hilarious, and then they went back to everyone having a turn.
"I totally should have grabbed Selvig!" she said as she took one of the beer cans that were being passed around. Water bottles too, because hey, heatstroke. But also: free beer. She was a college student, couldn't afford to pass up free beer.
Even if that meant she had to try her hand at the thing, after being slapped on the back a few times.
"Aww, damn," she said when she lifted it. Now she'd ended the party. No more beer.
She was about to go 'Sorry, dudes,' when one of the guys handing out the beer said, "Oooh," like he'd just figured something out. "Ain't she the first woman to try it?" he asked another dude.
"Yeah, we were handing out the places in line by the drinking contest, and I didn't want alcohol poisoning," said a ruddy-faced (wasn't like she hadn't taken advantage of the free beer) lady with arms about twice as thick as Darcy's.
Another guy blinked, and started laughing, slapping his thigh. "We were grabbing the shaft of the hammer!"
"Oh, yeah, and it went right up the moment she got her hand around it!"
The old man cackled. "Just took a woman's touch, heh!"
"Can't argue with its taste," free beer-guy said, saluting her with a can, and Darcy nodded. She resembled that remark.
"This used to be your hammer?" Darcy asked Thor.
"Yes, it is my mighty hammer Mjolnir."
Mew mew? "Oh, so it swings both ways!" she realized.
"It swings a great many ways, and calls down the lightning upon the enemies of Asgard."
"So why didn't it let any of those guys pick it up?" Darcy wondered. Looking up and down Thor, she thought, "Maybe it's just really picky when it comes to guys?"
"Mjolnir is meant to be wielded only by heirs of the throne of Asgard. The only other person named by Odin as fit to take the throne is my bro..." Thor looked puzzled for a moment, and then the same look of enlightenment appeared on his face as when that awesome redneck realized the hammer was into women. "Of course, this is one of your tricks! If a strange one…" he said, looking up and down Darcy's body in slight surprise instead of the nice Darcy was more used to from men. "One that Odin would not suspect!" he added, rallying. "But, you have brought me my hammer! May I have it so I may return to Asgard, 'Lady Darcy?'"
"I don't know, it's a nice hammer…" but, she realized, crazy dude. Nice on the eyes, but whatever got him out of town? "Eh, take it," she said, holding it out to the guy. When he had a secure grip, she let go.
Darcy winced as she heard a crunch. That didn't sound good. "That's totally not my fault."
Jane turned away from the cursing Thor to look at her.
"It's not! That thing's like, light! Do you have osteoporosis or something?"
"It is…" The blondie struggled to take a deep breath… "I will…" he reached down. "What, what is this?"
"I'll get it?" Darcy said, reaching down. She winced when his banged-up foot was revealed. "Ow, man. Do I need to drop you off at the hospital again?"
"My sons, we are descended in an unbroken line from the first Allfather of Asgard. Our family and its magics must remain upon the throne for the maintenance of the realm, yet I cannot argue with Mjolnir's choice of who is worthy," said Odin. "One of you must wed the Lady Darcy." As a Midgardian her lifespan would be short, and he could hope that either Thor or Loki would have proven themselves to Mjolnir again before that day came.
Loki's hand shot up, then hovered, hesitant.
"Loki, you may not be firstborn, but you are my son."
"But, I'm not exactly…" Loki grimaced and waved at himself, indicating his appearance, or so Thor assumed.
"What, because you lack a beard?" Thor asked. "You are no less fit to be Allfather for a thing like that!"
"Yes, my father Bor's father wore a beard and bound her chest," Odin agreed.
"…Grandfather was a woman?" Thor asked.
"No, she was the Allfather," Odin corrected him.
"Then how did she sire Bor?"
Odin stared at his son with his single eye for a moment. "I thought your mother handled the talk about the birds and the bees and the runes. In the normal course of things, the answer would be magic, but I am not the first man in our family to practice seidr. My grandmother was very much a traditionalist, and resolved that if Asgard needed a seidkonur, and only women could practice seidr, then he would be a woman. When I began to study seidr my grandmother was always after me to at least grow my hair out…"
"Did that not cease to be common practice thousands of years ago?"
"Are you a fool, boy? I know far too much of magic to argue with as powerful a seidkonur as my grandmother," Odin said. "You, it seems, know far too little. In time, this Darcy will inherit my throne, and Gungnir is all the manhood the Allfather needs. Given what Hemidall has reported of her dealings with you and these Shieldmates, she possesses the proper willingness to smite those who trouble her already."
This 'verse has She Is The King, as per Hatshepshut in another divine royal lineage. The way the Japanese Imperial family managed to remain on the throne regardless of who was actually ruling Japan is also interesting.
A lot of cultures where gender was mostly signaled by clothing had people get around the rules for what they could and couldn't do by crossdressing: as per Monstrous Regiment, there are tons of stories of soldiers and doctors having their true gender discovered only after they'd died.
Odin in mythology is known to have lived as a woman for several years so he could learn magic - given that Frigga in the movies clearly has training in how to use a sword, it's very likely Asgardian women would do the same thing for warrior training as the men would do if they wanted to learn how to use magic/advanced technology.
Odds are that Sif is just the first women warrior to be both openly a warrior (unlike Frigga) and openly a woman at the same time, while Odin's in the same position as Sif due to being openly a magic/magitech user and openly a male at the same time.
In Agents of Shield, Sif knows a lot about how technology works and how to use unfamiliar systems, which fits since Sif probably would have had to go to the computer science classes before she was old enough to put her foot down and insist on combat training instead. Someone needs to do fic about Loki and Sif disguising themselves as each other and sneaking into the classes the other one was supposed to be taking...