LONDON — A glowing Kate Middleton yesterday made what was dubbed her final solo appearance before giving birth when she christened a gigantic new cruise ship named the Royal Princess.

The Duchess of Cambridge cut a ribbon launching a four-gallon champagne bottle toward the hull, where it smashed as crowds cheered.

“I name this ship Royal Princess, may God bless her and all who sail in her,” said the duchess, who is expecting her first child with Prince William in the middle of next month.