Yeah..well, she's related to royalty now...have you seen what the rest of the royals look like? :p
I think she's above average pretty. Like a lot of the movie stars. They end up plastered all over the magazines with people gushing over That Dress at the oscars and the like. Less beautiful women than her (imo) have made entire careers out of their looks.
In this pic she wouldn't look out of place amongst the Beautiful People:
