Ok, here are my 2 cents on this one:
Based on your comment that it is you and your daughter and you are not using the room, I would suggest to not buy anything else. Take your time and think a little outside the box on what might be nice for you and your daughter.
There are 2 Houzz articles:
"Have an extra room? Lucky you."
I can't get back to the other one but it has the words "extra space" in it.
There are suggestions like a reading room, yoga room, meditation room, music room, garden room....
I would also like to suggest a stylish entryway room. A receiving room? Like a mudroom but with maybe 4 armchairs and a round table/ottoman. It is awkward when company comes in the front door and no one knows where coats or shoes go. There is also pressure for the owner to make them disappear.
Your sideboard and mirror can be your elegant landing zone for keys, papers, etc. Use a coat tree, umbrella stand, shoe bench, or go all out with hall trees/cubbies. You could even add a shredder in a basket so papers are dealt with right then. Paint it in a color you like that may add formality and get attention, like a teal blue, cherry red, chocolate brown, or deep grey.
Books could go in there too. As your daughter gets older this can be an away room for either of you, or allow her to hang out with friends or by herself. You are lucky to have this space! Keep us updated on it!
Q
Taupe glass backspl
Q