With respect, I will continue to use her videos and I will continue to take notice of what she has to say because I believe that she knows what she’s talking about.
She may not be your cup of tea but she’s mine.
I wrote "based on what I saw", and to be fair, I only saw that video so it was hasty in that sense. This was not a matter of taste, however (cup of tea) but the video. She keeps talking about the wrist rotating, and you already had a problem of finding a stiff wrist. The rotation is the same movement that you make when you turn a doorknob and it is the forearm that rotates along its axis. She talks about the right thing - you do indeed do this kind of rotation for that kind of music - but the wrist part makes you try to do the wrong thing.
She does, in fact move her wrist; laterally side to side, in a small movement, which is correct, but she does not say so. When she plays the 6th, from C (thumb) to A, she moves her hand with a small "wrist movement" - actually the arm moving slightly to the right. This is also important
because you don't necessarily want to stretch your hand out for that 6th (C to A) before playing - you can move to the A. That stretch or setting of the hand can in fact be the reason for your stiff wrist.
This is also the reason that I recommended Dr. Mortensen because he goes into this.
I have since looked at her Youtube channel. She does not teach much about technique, so you might want to supplement to get that side of it. I don't know if you also have a teacher to help you in this. She does seem to have some cool music things, and I can see why you like what she does.