your walls are looking a bit rough. Are you able to paint them? If you already have brushes and supplies, then that's just a $50 fix to really change up the feel of the room. Adding in supplies it'd be about $100 (could be less if you bargain shop).
The bed really needs a headboard. Amazon has some really reasonably priced ones. Something like this.
The random bits on the walls of above the windows/doors needs to go. More artwork is great, but properly hang it on the wall.
The curtain is too light and not properly hung. Get two panels of a heavy, more textured material and then add some tie backs for them.
For a more cozy look, add more pillows to the bed, a warm textured large rug, and a nice sized plant somewhere.
Rather than the two little side tables on "her" side, get one sturdy night stand. Something like this that has solid drawers for storing things. Add a side lamp to help with lighting. What is that floating lampshade by the black wall art stuff? It seems really out of place.
Only keep the chaise if you actually sit in and use it. I'd slide it a bit further away from the chest of drawers, more towards the corner. Put a nice reading lamp next to it and a large floor plant on the other end/right in front of the window.

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