Her youngest children, Knox and Vivienne, turn 2 today, and though Angelina Jolie says that she and partner Brad Pitt are usually exhausted from raising their brood of six, she can't help but want more. "We always have this thing, first thing in the morning, where we're really, really tired, and we look at each other and we wonder, Are we ever going to get sleep?" Angelina, who says that she and Brad are basically "waiters" to the kids, told Good Morning America. "And yet we still love the idea of having more children." And according to Angelina, it's Maddox, 8, Pax, 6, Zahara, 5, Shiloh, 4, and the twins who will decide when their parents tie the knot. "I think it would be hard to say no to the kids," she said, but so far, "they're not asking. They are very aware that nothing is missing."