Kate Middleton is rumored to have just made her last public appearance and will be taking her maternity leave as the due date to her first child grows closer.

"The cruise ship christening on June 13 will be her last official solo engagement," a source told The Mirror.

On Thursday morning, the Duchess of Cambridge formally christened the Royal Princess cruise ship, the newest addition to Princess Cruises' fleet, according to the Huffington Post.

Prince William's wife was chosen as the "godmother" of the ship, and she was there to officially name it.

[For photos of Kate Middleton at the cruise ship christening click HERE]

The Duchess walked up to the podium and said, "I name this ship Royal Princess. May God bless her and all who sail in her," she cut the ribbon which broke the ceremonial bottle of champagne on the hull.

With her due date just around the corner the arrival of the baby means that the couple is unlikely to carry out another tour together until 2014. Sources revealed that the Duchess of Cambridge wants to focus on being a mother before she returns to her public duties.

This is not to say that Middleton does not care about her commitments, "She takes her royal role very seriously and is looking forward to taking up her duties when her maternity leave has finished," an insider said.

The paper reported that in the past Prince and Princess of Wales took an infant Prince William with them on their first tour after his birth and the Duke and Duchess of Cambridge have the option of doing the same thing.

For more Kate Middleton pregnancy news click HERE.