I love the mirror. I also love removable decals for kids rooms ,they change what they like yearly when young. I also do what you did and keep the walls really neutral since they also change their favorite color about the same timing. Some pictures of her are nice and some place for books and toys along that wall would be great . keep all that quite low so she can reach it all and the decals above. The furniture is pretty fancy so I hope she stays a girly girl for a long time. I like more simple furniture in kids rooms but now it is there embrace it for now. I would also ask her what her favorite color is and use it with the pink. I have to say I hated pink when I was little and I still don't really love it, at best in small doses. I also love a chalk board down low for self expression and to save the walls and a bit later room for huge corkboard for posters, pictures all kinds of stuff kids collect. This is her space and IMO never forget that.

Love the idea mentioned above about removable decals. Reminds me of the Colorform kits of yesteryear.

Suggest a bookcase (secure to wall) for toys and books, etc which will be really useful and there are all kinds of cute wall decor options

I love the cubbies idea but I do prefer to have the toys in the playroom as she will be in these otherwise instead of going to sleep each night. This is a lost battle of course, do you all have any tips or idea for the wall area without a storage cubby By chance in case it doesn’t work out ?

I hear you about toys in the playroom. BUT you'll still need storage for books, stuffed animals and various other treasures to be displayed. Storage shelves or cubbies seldom go to waste.....

I think the cubbies and decals would be great. We did decals in our 3 yo daughter's room (floor to ceiling birch trees) and they're awesome. I also love the storage cubby idea. I got a kallax unit from ikea and put the 3 sprouts storage baskets in them. No toys in there at all. I store winter jammies, next size up clothes (this was more important when she was younger but still works now), stuffed animals, and random other stuff. We use the IKEA picture ledges for books on the wall behind the door, which you could also do, or you could use the storage cubbies for books as well.

My niece did a family tree with pictures of her daughter's family.

This photo is a little washed out, but you could use three coordinating paint colors to create an accent wall. Then paint the rest of the room one of the colors. Add a couple of framed photos of your daughter.