Try 2 on a window and take a picture.

Do u have pictures of the other walls?

If you put a bookcase or some kind of focal point in between the windows then I think just one panel each window looks fine but if nothing is going there then I would do 2 panels.

Like the idea suggested by Melissa Felber to place a piece of furniture in between the 2 windows. Then you can sweep each panel to the side. In this case, of course, not a bed....but love this example of using 1 panel on a window instead of two.

Do u want WOW n an ethereal feel to this room? I used those really cheap shears from ikea ( $4.99 ) n placed it on the entire wall covering 2 walls. I would do the window wall n the wall behind the couch. u could use an accent/textured behind the couch. it gives a room very ethereal feel. something like what I did for my BR.

Wow, so pretty londonvon! Inspires me to want to do this in our master bedroom.

Super easy n very cheap to do