history shows time and again that even 'uglier'-deemed newborns can become real swans in later life - one definite example of this is one John F Kennedy jr., an ugly infant (google it) who grew out to become one of the finer male specimens if you ask moi!
Although I also am of the opinion that those who were deemed beautiful as newborns, tend to stay that way mostly: look at Felix of Denmark for example, a gorgeous newborn and now, young boy, very handsome. Examples like that galore (Leonor of Spain, yep, she does qualify here I think)
I think as far as I've been able to see, Christian's little sister takes after her mother, Mary. I noticed for instance the in my view quite a big distance between upper lip and nose, a feature that Mary also has, and which, sorry folks, is not in my view one of the seven signs of beauty.
But indeed, what does it matter. Hopefully she's equipped with a decent brain and an even more decent heart and that's all a human needs to get going, really.