Will there be something along the wall on the other side in the kitchen? If not why not turn the window into a full opening ( a pretty easy thing to do ) so you'll have potentially even more light and a new flow pattern. Otherwise remove the window and replace it with a sheet of glass in a simple surround - you could have the glass frosted along the bottom half to obscure any view of dirty dishes or cluttered countertops.

Hi. You can buy fretwork panelling. I'm not sure on the style of the house but you can get a few patterns, mostly moroccan I suspect. This pic is from Elle decor

Hi, Sandra, In my opinion this would depend on how dark you need the room to be; if you need it dark for sleeping then I would suggest using a blind(roman or roller) inside the recess, and then having a more sheer curtain on a track going across the top of the entire wall -- you could use a pair of curtains for each window; if they are lightweight it wouldn't affect the radiator in the middle if you wanted to pull them back. The sheerish curtains would work with the overall feel of the room. Alternatively you could still have the blinds in the recess and the single track, with more tailored curtains -- one for each window, so when they are pulled back (with a holdback) there would be one on the left of the left hand window, and one on the right of the right hand window. Treating them as one window, in effect

You will still need structural engineer calcs for a window, as you would need for a walk through. ( just incase you weren’t aware )