Pippa Middleton welcomed her first child with husband James Matthews.
The couple welcomed a baby boy on Monday at 1:58 p.m., local time, weighing 8 lbs. 9 oz., PEOPLE confirms.
“Everyone is delighted and mother and baby are doing well,” her representative tells PEOPLE.
The newest addition to the family makes her older sister, Kate, an aunt for the first time. The royal mom of three likely has plenty of sage advice (and newborn clothes!) to pass on to her younger sister, who was one of Prince Louis’ very first visitors after his birth in April.
Pippa followed in the footsteps of her royal big sister by giving birth in the Lindo Wing of St. Mary’s Hospital — the same place where Kate and Prince William welcomed all three of their royal children.
A source previously told PEOPLE that Pippa and her husband, James, are looking forward to settling down and “having children and leading a quiet life.”
And their new baby will have plenty of little playmates. In addition to cousins Prince George, Princess Charlotte and Prince Louis, Matthews’ younger brother, Spencer Matthews, welcomed his first child, a son, with his wife, model Vogue Williams, in early September.
Pippa, 35, and James, 41, tied the knot last year on May 20 at St. Mark’s Church in Englefield. Her royal nephew and niece, George and Charlotte, served in the bridal party.
Middleton confirmed her pregnancy in a June column for the U.K. supermarket monthly Waitrose Kitchen magazine. The then-expectant mom revealed that she did not battle severe pregnancy sickness, or Hyperemesis Gravidarum (HG), unlike Princess Kate.
“I was lucky to pass the 12-week scan without suffering from morning sickness. That meant I was able to carry on as normal,” she wrote.
She stayed active throughout her pregnancy and documented her fitness regime in her ongoing column.
“I’ve noticed my body change, but through exercise I feel it’s being strengthened,” she wrote. “I’m fanatical about sport and have looked at loads of books and websites on exercise during pregnancy, but have been disappointed by the limited technical information what you can and can’t do.”
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At the start of her third trimester, Middleton shared that swimming had become part of her routine.
“From personal experience, I’d confidently say I find it has been the most enjoyable and rewarding form of exercise since I found out I was expecting,” she shared. “It’s comforting to know that it’s safe throughout pregnancy, and you don’t need to adapt and change too much (unlike most other sports). It’s so good for you that you could swim every day – as long as you don’t overexert yourself – right up until the end of the third trimester.”
In her final column, she revealed that she had turned to meditation to help her in the late stages of her pregnancy.
“I was skeptical at first, but after practicing this discipline for the past month I have noticed a huge difference in my mental wellbeing and sense of clarity,” she wrote. “It’s a good idea to take some wellbeing time for mummy-to-be now and, most importantly, for the future.”
News of Pippa’s pregnancy was first reported just days before sister Kate was admitted to St. Mary’s Hospital in London in the early stages of labor with Prince Louis on April 23.