Pippa Middleton Welcomes First Child With Husband James Matthews The sister of Kate Middleton, the Duchess of Cambridge, has given birth to a boy. The baby was born on Monday afternoon weighing 8 pounds and 9 ounces. Pippa announced her pregnancy in June in her fitness column for 'Waitrose Weekend' magazine. A Kensington Palace spokesman says Prince William and Kate are "thrilled" for the couple. The arrival comes just a day after Prince Harry and Meghan Markle revealed they are expecting a baby. Middleton and her husband were married in May last year in a ceremony attended by royals and celebrities.