Okay, so I have several ideas.
I recommend getting a baby toothbrush (one with a suction bottom), your excuse can be that the dentist recommended it
It's useful for getting into tight spots in your mouth.
I also recommend keeping two stuffed animals on your bed at all times. I recommend squishmallows, they are really popular right now. I recommend at least one common animal type one, and one strange one (like an axolotl!). One of them needs to be bright, but the other one is your full choice of color.
Here's a few more good things to decrease the age-look of your room:
Tutus, skirts on hangers, fairy lights (holiday lights work too if they are small), depending on how young, diapers might be reasonable to keep on a shelf (cover it with a blanket if people are over), baby wipes in the bathroom and one of those cup-bucket things that parents use to wash shampoo out of children's hair without getting shampoo in their eyes, sticker books and put some of the stickers on the surfaces around,
a hanging see through curtain thing over your bed
I wouldn't do all of them, just choose the ones you're interested in