Kate Middleton celebrates 30th birthday

Prince William's bride, Catherine, turns the big 3-0 Monday.

So how do you celebrate your first royal birthday?

When you're the former Kate Middleton, now Catherine, Duchess of Cambridge, you attend a film premiere over the weekend with your husband -- and prove that sometimes the people going to the movie can be bigger stars than the people in it.

Pictures: Will and Kate at royal premiere of "War Horse"

While the weekend was full of fun, palace officials said the Duchess of Cambridge's birthday celebration will be a "low-key and private" affair.

It's been just eight months since her wedding to Prince William, but the duchess has looked in recent appearances like she'd been performing royal duties all her life, wading into adoring crowds and meeting the ill and the less fortunate, Mark Phillips reported on "CBS This Morning."

There were high hopes that Kate's looks, charm and levelheadedness were exactly what the royal family needed and professional royal-watchers like Ingrid Seward say Kate has delivered.

"Kate is like the golden ticket for this family," Seward said. "She's just what they needed and it's a love match so at this moment in time you couldn't get anything better."

For more with Mark Phillips on Kate's big birthday and more royal talk with Victoria Arbiter, check out the video above.