Hi can someone tell me how this soft ethereal lighting was created?

I love it a lot, its by the photographers Joseph & Yuki

Looks like two lights. Key is a large soft light above and on the right of the photo. Second light is just illuminating the background -- bright enough to knock out the shadow from the key light.

Here is my guess:

Large diffused source (might even be natural) from near directly behind her turned way down if artificial.  Look at the shadow of the flower on tha back of her neck just above the dress line.  To me that shows the direction of the light.

I am then going to say that the her face is ambient.  As for the background, I am not sure.... It could be getting enough off the diffusion source. to be lit like that --- notice the fall off right to left.  Perhaps the background is dodged a bit and the face burned a bit too.

Those who know more than me will hop in and correct me, I am sure......

Lets see your attempt. Maybe we can figure out how to adjust it.

It's thread deserves more love as I would like folks who kow better than me to opine....

I'm going with two lights and some post work on the shadows.
One light for the background to evenly light it.  A large softbox behind and just in forward of the model feathered for the edge of the light falling on her.
I see post work to modify the shadows in the hair.  The hairband maintains a constant exposure value even as it's being surrounded by shadows on both sides along the top.  The front of the hair along the back bump falls into shadow quickly while the back of the front bump that is practically touching it is unaffected even as it curves back, they should both have fall off as they recede.
The front of the face also looks to have had the shadow enhanced for effect.

I think this was shot with window light

I think the falloff on the wall eliminates natural light. I think one great big light source like a 5 or 6 foot octobox about 5-6 feet from the model feathered towards the wall a bit.

Maybe?