Obviously, part of this is just because I have a massive crush on Sif, the character, and Jaimie Alexander, the actress. I love her...why?

Lady Sif is sort of the MCU equivalent of Wonder Woman, an immortal who combines strength and nobility with a sense of warmth, compassion, and emotional openness. 

She doesn't get a huge amount of screen time but comes off as an incredibly well-rounded character, especially in a genre where many female character are assigned valued based on how well they can mimic the traditional cliches of male Action Heroes.  

Sif is able to switch from playful and cocky, to stoic and serious, to gentle and supportive, depending on the situation (as benefiting a literal goddess).

In other word's, she's Girlfriend Material of the absolute highest quality! 

Beyond that, I love that she's so high-key Romantic in her feelings for Thor. Having your Badass Warrior Princess character mournfully pining as she gazes across a crowded room at her lifelong friend, her eyes brimming with unspoken feeling... it's exactly the kind of over the top, melodramatic bullshit that I love about the Asgardians and their weird alien/pseudo-Shakespearian/mythic warrior culture. 

At the same time, she's never fawning in her interactions with Thor. They banter like old friends and flirt in mid-combat. 

Sif tries to counsel him when she thinks he needs perspective or patience. 

She advocates for him when he's not around.

To me it's a very romantic set-up, a long-term friendship based on loyalty and mutual trust with the potential to develop into a very deep relationship. (Though, flipping it around, I can definitely see how female viewers might not appreciate their Super-Hero/Immortal Warrior Woman power fantasy character being portrayed, pining from the sidelines for several centuries).

Plus, their dynamic has this tropey, genderswap thing going on. A Fantasy Prince and his Loyal Female Knight. Except the Fantasy Prince is a giant Viking Immortal with a magic hammer and he and his girlfriend ride into battle side by side which is both hot and romantic to me.

Of course the downside  to Thor x Sif as a relationship (also maybe what makes it appealing)... is that it's all potential. As far as we know, Thor is either unaware of Sif's feelings or does not reciprocate. Which is weird because Thor generally comes off as a very socially/emotionally aware guy... at least in the context of Asgardian society. 

One of my favorite things about Thor is that he's confident but honest and genuine as well. He never comes off as a "ladies man" i.e someone who puts on a smooth, crafted persona specifically to interact with women. 

However, he clearly seems to be aware when women are attracted to him (Jane Foster, the woman in the subway)...so how come he doesn't seem to notice the very obvious torch Sif is carrying?

My personal headcannon for this is that they either casually dated as adolescent (whatever age that is for Asgardians) or came very close to it. But then Frigga and/or Odin stepped in, took Sif aside and basically told her to hold off because they thought she had the potential to be a good queen.

Before his time on Earth, Thor was reckless, arrogant, impulsive, and quick to violence. He wasn't ready to be a king or a committed lover. And so Sif was encouraged to do the responsible thing and wait. 

The irony being that by the time he had matured into the person he was supposed to be, he had met somebody else.

To me, there's something there that mirrors the fall of Asgard. Why not wait? They're gods after all, there's always going to be more time.

Then Thor gets banished and comes back different. He's met a mortal woman and doesn't want to be king anymore. Frigga, who Sif always thought would be her mother-in-law one day, is dead. 

Thor goes searching across the universe and then Odin sends her away from Asgard. And when she finds her way back even her home is gone. Her people live on Earth now, or at least the fraction of them that still survive after Hela, Surtur, and Thanos. 

Thor is gone again, traveling through space with a bunch of mercenaries she’s never heard of.

Maybe I'm just projecting because I want someone in-universe to mourn Asgard and everything those people must have lost in what must seem like a very short amount of time to them.

I always thought Thor x Sif had the potential to be a very stable, well-rounded couple. However, given Thor's general arc in the first two movies  it would have seemed a little off, thematically speaking, if he ended up with the immortal warrior princess/long-time friend that his parents wanted him to get with all along.

However, post-Ragnarok/Endgame I think there is a lot of dramatic/narrative potential to a romantic reunion between Thor and Sif, someone who knew him before everything started and can see how much he has changed. Maybe someone he didn't realize how much he cared for until she was gone. 

For her it's a second chance at something she thought was lost, a piece of her past that's come back damaged and different but still worth fighting for.  

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Obviously, this is all conjecture. There's no guarantee that Sif will return in Thor 4. As a shipper part of me is hoping for it, however as a fan of her character I'm also worried about her being crammed in and either sidelined or mischaracterized by the those behind the scenes.

If she shows up in the Loki show, that's more screen time and room for character development. 

However, I'm not hugely interested in Loki's show and depending on the direction it takes I'm not sure that it will play to her strengths as a character. My dream scenario was for Sif to have her own Xena-style high fantasy adventure (with Thor showing up in a supporting role) but that’s seem very unlikely.

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