I think she mostly resembles her dad with her expressions, because she has his lips and chin and the shape of his face, and his eyes I think. And maybe his nose too? LOL. That's pretty much the whole face, isn't it?
But then she has something of Caroline's ..... ?deportment? Countenance? And of course, she has her mother's coloring and cheekbones....
Where Pierre is a total clone of Stefano, Charlotte inherited a wonderful combination of both parents. Andrea has so much of the bone structure of Caroline, but he, like Charlotte, has the Casiraghi lips, I think, and the Casiraghi eyes and expressions.