There are two ways she can get recognition. First is to persuade Duane to put her name back on as Co-Director. The second is to create a loud scandal that tells everyone what she did on the film, a viral message that tells the story behind the story. The two are mutually exclusive, and the latter course is an awful idea.

Even if the reasons behind Duane's turnabout are bullshit,  going behind his back is going to rub the right people up the wrong way. She might be the greatest editor in world, but if she gets a reputation as 'that woman who raised a stink about being co-director', then her career could suffer. Especially so if the reasons aren't credit-stealing bullshit and more "well, she was only in the editing room and didn't actually direct anything". If she tries to damage Duane's reputation then he'll just come after her - and that's a battle she'll lose.

And there's no guarantee that her story will even be heard by those she wants it to reach. I bet Jessica isn't the only person to feel that she's getting short-changed, but I've never heard a story where, say, some assistant DoP finally achieved recognition for the look of a film he felt he influenced more than the DoP.

If she can't persuade Duane to give her due recognition, then she should just take the editor credit and move on. It's just not worth it at this point in her career. And yeah, don't work with the arsehole again.

Speaking as someone with no film experience, why not just put it in her demo reel (or the like). Have future employers see it and make of it what they will.

If this was a joking matter I'd ask if Asylum was hiring

But, being out of my depth, I'll just ask if editors can get a directing credit (or even a writing one) if what comes out is different enough from what went in. Although, now that I think of it, for a documentary most of what a director would be doing is arranging the footage, so... I'll go away now.

That's pretty foul. Since there's nothing she can do contractually and the prints are struck, the best course of action off the top of my head would be to contact IMDb with the video where's she's mentioned as director and make a case for her to get her listed as such, but uncredited.

The DGA usually opposes co-director situations for this among other reasons, but discourse with someone from there, or anyone who deals with arbitration may provide some ideas.