She wasn't even the best supporting actress in that movie, let alone the year

Personally I dont see it. She was good but not amazing in my opinion.

Honestly, maybe. I looked around to see who else might get nominated in the supporting actress role and I don't see many strong contenders. As the article notes Samantha Morton has a chance from the same film (as Circe) but I don't know if I have a strong feeling from either of them.

Looking at the historical winners while there are absolutely some greats, there are plenty of just fines as well.

I think she could probably win.