Firstly, color the bathroon walls in pink, in a bubble gum pink color, or use some Barbie stickers or a large Barbie wall decal.
Choose Barbie linens for your little girl bathroom.
A pink shower curtain with Barbie printed on it will do the work.
And on top of it, a favorite Barbie doll can be placed in a box near the mirror. You can think of a vintage Barbie like here, vintage Barbie...breakfast at Tiffany's!
Don't forget the most important thing: Barbie towel for kids! On Amazon.com, you can find it for 13.92 USD, 100% cotton:
Barbie bath towel and wash mitt set
Note: Thank you to all my visitors for buying from Amazon through my ads, you all are helping me to pay my breast cancer treatment and keeping a healthy diet.