As a young teen, she was shy and awkward. "She wasn't really confident," says a former classmate. "The poor girl, we felt sorry for her."
Now, of course, she is set to become one of the most famous women in the world. As anticipation mounts over the April 29 wedding date, those inside Middleton's circle say she will draw on her quiet inner strength.
"While she's not the sort of person who bursts through the door and grabs people's attention, she very much has presence," says a friend. "She draws attention to herself in a very unobtrusive way."
So far, say observers, she's proved herself a quick study on the royal stage – despite little-to-no formal training. "There's no charm school for princesses," says Ingrid Seward, editor-in-chief of Majesty magazine. "It's sink or swim."
For much more on Kate, including her stellar style and candid photos of her childhood, pick up this week's issue of PEOPLE on newsstands now