Editors were saying they were tired of talking animals in picture books when I started sending manuscripts out in 1980. So take it with a grain of salt.
My picture book CINDER EDNA, still in print after decades, was originally going to feature pigs. Trust me, I didn't have pigs in mind when I wrote it--and I was really glad when they decided not to.
Oh, and some were also tired of fractured fairy tales way back then. And look what's happened since.
Same thing with princesses. Write your story the way it feels right to you.