Before we know it, Kate Middleton will be an aunt! The Duchess of Cambridge's younger sister, Pippa Middleton, announced her pregnancy in early June, so now many fans are wondering: When is Pippa due with baby No. 1?

When she revealed the special news earlier this summer, she shared she was past three months at that time, however, she didn't share the baby's gender or exact due date. "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 in a weekly column for Waitrose Kitchen Magazine at the time.

pippa middleton

If Pippa was actually 12 weeks along (or more) at the time of her announcement, that would mean she could be due sometime between October and December of 2018. If that is the case, her first child will be born the same year as Kate's third royal baby, Prince Louis! Talk about cousin bonding.

Since Pippa has had a baby on board, she's been turning to her older sister — who has been pregnant three times — for advice along the way. "They confide in each other about everything," a source previously told Life & Style. "When they were younger they'd always share stories about boys and school life. Now they’re sharing pregnancy stories."

"She’s been giving Pippa lots of tips on what’s to come and helping her with the nursery," the source added. "She’s also given Pippa some of George and Charlotte’s hand-me-downs but is obviously keeping some for Louis and her next baby." The insider continued, "Kate and Pippa have had so much fun shopping online for baby clothes and accessories!"

kate middleton and pippa middleton

Pippa has been showing off her baby bump in a plethora of stylish maternity outfits over the past few months, and we must say — we can't wait for her little bundle of joy to arrive (whenever that may be!).

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