Windows in nursery… curtains? How high? Art above?

Not sure what to do with these windows. The blinds are installed in the windows themselves and can’t be changed easily. Do I add curtains? If so… what height? I have a large, walnut wood crescent moon I wanted to hang above the windows, but afraid it will clash visually with the light. Also open to other suggestions! The room is long and narrow, so the layout is kind of shotgun style.