She apparently dumped Michael Sheen to get further in her career; hence, why she married Len Wiseman. She was with Michael at the time of Pearl Harbor.
And Len's ex-wife claims that Kate stole Len from her on the set of Underworld.
As for the always looking glamorous in candids, I dont think so. She always looks fairly casual. And as for the pedicures, thats hardly a sign that she's a single girl on the prowl! And look how much we rip into celebrities when they're out and about looking like dags- she makes the effort because she knows the cameras are around, I don't blame her.