Of course Kate’s tough as nails. You aren’t a punching bag for the British press for 15 yrs (with no public meltdowns) unless you’re steely as they come. I think because Kate isn’t a social butterfly amongst the aristos, and because William seems to be the dominant partner people think she’s meek and mousey. But it’s really more that she reads people well, and knows most of those people aren’t her real friends, and while she gives guidance to Will, she knows it’s his own future, and his family.