There's a great disturbance in the fandom about whether Sabine is Force-sensitive or not. So let's take a look from the beginning.
In A New Hope, Obi-Wan explains the Force as:
It's an energy field created by all living things. It surrounds us and penetrates us; it binds the galaxy together.
And according to George Lucas himself:
In Rebels, Kanan uses Obi-Wan's explanation for the Force more than once. There's an important conversation in Trials of the Darksaber, which is related to this and to Sabine.
Hera: Or maybe because she doesn't have the Force, you don't believe she can do this?
Kanan: No. The Force resides in all living things. But you have to be open to it. Sabine is blocked. Her mind is conflicted. She's so expressive and yet so tightly wound. She's so...
Kanan never says Sabine doesn't have the Force. On the contrary, Hera says she doesn't have it and Kanan says no. What Kanan says implies that Sabine does have it, she's just not open enough to wield it.
Keep those quotes in mind for later.
Now, we have to address the Bantha in the room: the midichrolians. We're introduced to this concept in the prequels trilogy, I believe. It serves as a more technical explanation of the Force. The SW fandom wiki offers this definition:
Again, the midichrolians are in all living organisms because the Force resides in all living things.
As far as the movies go, we don't know how high the M-count has to be for someone to be able to wield the Force. We just know Anakin has a count of over 20.000 and that it's a very high number, so he's very strong in the Force.
We can assume that the higher the midichrolians, the more aptitude the user has in the Force.
I'm guessing Sabine has a low M-count, thus limited abilities in the Force because of this line in episode 2 of Ahsoka:
Huyang: I have know many padawns over the centuries, and I can safely say your aptitude in the Force would fall short of them all.
Some people interpreted this line as "Sabine isn't Force-sensitive at all." What I understand from that line is that Sabine sucks at using the Force.
Either way, midichrolians haven't even been mentioned in the show, but I've seen people talk about it regardless. I find most discussion of this kinda pointless because there's not much to go on, so we can only speculate.
Moving on. In episode 3, Ahsoka trains Sabine blindly so she has to rely on the Force to see. I think a lot of people missed that Sabine did, in fact, use the Force in that scene. Watch carefully.
2:16. After Sabine has grown impatient for not succeeding, she finally manages to sense Ahsoka's presence (she still couldn't see and Ahsoka didn't touch Sabine) and fight a little, until Ahsoka stomps on her foot and Sabine falls to the floor.
Ahsoka: Anger and frustration are quick to give power. But they also unbalance you.
Why would Ahsoka say that in the first place if Sabine hadn't used the dark side of the Force? She probably struggles with the light side because it's so different from what she's used to as a mandalorian. It's more aligned to her nature.
Later in the same episode, this conversation takes place:
Sabine: I can't use the Force. I don't feel it. Not like you do.
Ahsoka: The Force resides in all living things. Even you.
Sabine: If that's true, then why doesn't everyone use it?
Ahsoka: Talent is a factor. But training and focus are what truly define someone's success. Not everyone can handle the type of discipline it takes to master the ways of the Force.
This fits perfectly with Obi-Wan's quote and what George Lucas said in the interview. This is consistent within the Star Wars universe and Dave Filoni's previous work.
It does not break the canon, it does not retcon anything. We simply hadn't seen before someone training to use the Force and struggle so much with it.
And to me, that is far more interesting than having every single main character being just overly and naturally competent with the Force. You don't have to be the Chosen One to use the Force, you just have to have enough determination to put in the work.
Back to Ahsoka. In episode 4 (the latest episode that's come out since I'm writing this) Sabine manages to do a very slight Force push during her duel with Shin. I know many people will disagree with me, but just watch the scene again.
1:22. Shin disarms Sabine and knocks her to the ground. Sabine extends her hand and Shin is slightly pushed back. Her arm falls down, her head turns to the side.
I've seen multiple people say Shin did this in anticipation (when has anyone everyone done that?) and that Sabine didn't Force push her. But the thing is, there's a Force push sound effect. Listen closely. It's faint and short, but it's definetely there.
I think Shin's line also confused a lot of people.
This is not "Sabine tried to use the Force and failed and Shin reiterates it." Again, there's a Force sound effect. That should be proof enough that she's somewhat connecting to the Force. They wouldn't put it there if she wasn't using the Force.
I think Shin and Baylan, as sith/dark jedi or whatever they are, see the Force only as a means to power. That's what Baylan is seeking with all this anyway: power.
Someone with low Force-sensitivity like Sabine would seem totally powerless to them. Everyone has been telling Sabine she's not good enough for it (Huyang, Shin, even Sabine herself.)
So, you can totally disagree with me on this, but I personally interpreted that line as Shin telling Sabine to quit while she's ahead. If she'll never be as powerful as the rest of them, why even bother to try? But Sabine, as the stubborn mandalorian she is, still continues to try.
I think Dave Filoni is painting a very clear picture: Sabine can indeed use the Force, but she's not naturally skilled at it. I think she might still have some sort of block from it, like Kanan said. The show seems to be slowly building up to her wielding the Force more succesfully, though. Starting small, one step at a time.
With Sabine's decision (she didn't have much choice, if you ask me) near the end of episode 4, I do wonder if Sabine will be a dark side user. Shin and Baylan use the dark side but they don't seem to be consumed by it. We'll just have to wait and see.
I understand that people think that Sabine being Force-sensitive diminishes her character, but so far I don't think that's the case. She still uses her blasters and some mandalorian tricks up her sleeve. This just adds another layer to her character. Natasha Liu Bordizzo said in an interview somewhere that Sabine changes fighting styles frequently, and I think we'll see more of that soon.
As long as Sabine stays true to her mandalorian ways, I'm fine with it. How cool would it be to have a mandalorian-jedi in the mandoverse? Sabine has been kind of disconnected to her mandalorian heritage for a long time now, and I'm sure she won't be a regular Jedi, if a Jedi at all. She's a special breed, one of a kind. Who knows, maybe she'll help to bring balance to the Force after all.
If Bo-Katan can walk both worlds, then so can Sabine.
