I’d get a bigger rug so they have a soft surface to play on- ikea has some cute ones. Get some frames for animal prints or have your kids do some painting and get those framed. If you have the money, get a bed with drawers for storage of toys- if not, get some bins that can slide in and out from under the existing bed. If you have time to paint I would do that too to add colour- maybe get your kids to agree on a colour for the room and you can even paint the white furniture. I really like the light mint with pops of coral colour. I don’t know how you feel about those light projectors but they look neat.