Is that a double window behind the sofa and a single window with the arch on the other walls?

With this small a room, dark drapes along with dark furniture visually make the room seem smaller.

Consider getting matching mini blinds for each of your windows and hang them very near the ceiling so the arch will not matter. J C Penny sells vinyl (in a variety of colors), wood and faux wood window blinds (in a variety of finishes), including vertical blinds for patio doors and larger windows.

I'm not usually a fan of sectionals but in this unique space, a sectional in your corner and a pair of storage ottomans for toys when not in use are about all you have the room for here.

Between the windows, you could add wall shelving to display family treasures. These kinds of shelves are easy enough to hang -- just add screws at the studs through the board at the back of the box. The boxes that are used as shelves can be made in any size you need to fit your wall or use multiple boxes.

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A corner shelf (above head height for the tallest person sitting on the sofa) hung in the corner to the left of the larger window(s) could hold a lamp behind the sofa rather than always needing to use the brighter overhead light. Creating the box double shelf as a corner shelf would provide a shelf for the remote and/or game control, etc.

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