Paint is a very inexpensive way to change a room. If you really don't like it I suggest paint, it will make the biggest impact.

Adding taupe or beige to the walls, in most hues, would blend in too much with the draperies. I love the lavender in the bedding. It would pull the room together if you were to choose a grey paint that had elements of lavender or berry and silver. The color would be subtle, neutral, relaxing as well as refined. This slight shimmer will pull out the subtle nuances in the marble. As the headboard is already so interesting, it would be too busy to add anything too ornate on the wall. To open up the room and increase the light, you could hang a mirror. I would select an Art Deco style with metallic accents to continue pulling together the room. The marble is lovely, but combined with the sleek lines in the bed and bedding it creates a very smooth appearance. To create warmth, it is necessary to add additional texture. I would add a soft, plush or high pile area rug by the bed. How nice would it be to step out of bed on to that?

Better view of the wall and bed ..pls help me with color combination of curtains n cushion n what all can I do to highlight the wall ?

No experience with babies actually - but seems there are endless combinations - this was just the first / type in and select "Stories" for good articles like this with at least 2 ideas. Many "Photos" on houzz. "Shop" too. [https://www.houzz.com/magazine/guest-picks-desert-beauty-for-the-babys-room-stsetivw-vs~29205805[(https://www.houzz.com/magazine/guest-picks-desert-beauty-for-the-babys-room-stsetivw-vs~29205805)