'Princess' is a good word, as is 'girlish', 'pixie-like' and all these other things. I personally find it a bit boring, it's all been done before. The amount of times you read reviews of bands and it's an all-girl four-piece, and they talk about what the women are wearing... you'll never read a review that's like: "Male singer Thom Yorke, who was dressed in a white t-shirt and jeans..." You would never read that about a man.
