Is it that bad of a layout? This is my main music listening location now. Replacing my 13x14 study with M5s. That would be the worse outcome possible. The nulls are not that bad, I'm just trying to improve things. Also, it's not the speakers she objects to, it's moving out any more of her stuff.
It's hard to second guess someone else's decor decisions without more photos. I take it there's a fireplace on the left longitudinal wall? If so, I'd consider relocating the sofa to face it directly, with the accent chairs on either side to form a sociable seating group. That would get rid of the primary sight-line of the stairs from the main seating area. I would have the loudspeakers straddle the fireplace mantle. If there is no mantle, it might be a good spot for a TV bench.
Good home decor has symmetry, repetition, and proportion elements. The short curtains, low curtain rod placement, and crooked picture frames mounted above the door archway call unnecessary attention to the short ceiling height (even though it's not short), and the hanging pieces are the wrong scale for the room size. Those three frames ought to be mounted to the right of the door arch to balance out the mirror on the left. Make sure the grouping is at the same eye-level height as the mirror.
The cushions are the right size but too close to the color of the room; may I suggest bright yellow, cobalt blue, forest green, or white?
If she can buy into making those revisions, then you can upsell her on a subwoofer.
