According to the bombshell report, both duchesses, 36, are preparing to raise their new bubs together as 'one big, happy family.'
A Kensington Palace source tells, 'Kate and Meghan bonded over the men they married. Now they're bonding over being pregnant together.'
While the pregnancies are the subject of plenty of 'palace buzz', In Touch claims the duchesses have 'only shared the news with close family and friends.'
For Meghan, In Touch claims the pregnancy is not just a huge joy but an 'enormous relief.'
'She was a nervous wreck about conceiving,' a palace insider allegedly said, not only because of her age but 'because it didn't happen with her first husband,' producer Trevor Engelson, from whom she split in 2013 after two years of marriage and nine years as a couple.
In Touch sensationally reveals that 'the pressure to give husband, Prince Harry, children felt like a huge weight on Meghan's shoulders.'
'Everyone expected her to get pregnant immediately.'
Meanwhile Prince William, 36, was 'initially shocked when Kate told him he's going to be a dad again', but now he sees it as a 'happy surprise.'
'He and Kate have always wanted four kids,' the source tells.
And this time around, adds the source, Kate gets to share her pregnancy journey with not only her young sister Pippa, 34, who is due with her first child in a few months, but her new sister-in-law, too.
The US publication further claims the 'new duchesses are reportedly loving sharing their journey together.'
In Touch reveals Kate 'has penned a pregnancy food list for Meghan that's full of nutritious things to eat and is advising her on how to balance motherhood with life as a royal,' says the source.
Fitness enthusiast Meghan, whose mother Doria Ragland is a yoga instructor, is returning the favour by teaching Kate pregnancy yoga.
The publication adds that the two pregnant women are happily letting their husbands dote on them.
'He brings Kate tea and cookies in bed,' including lavender biscuits which are known to help with nausea.
The source adds that Kate is 'convinced she's having another girl because she's having the same cravings for sweets that she did when she was pregnant with Charlotte.'
Meghan is hoping for one of each - a boy and a girl - the insider tells In Touch.
'This is a dream come true for both couples.'
The royal family is yet to respond to In Touch's report.
Listen to this weeks New Idea Royals podcast to find out what REALLY happened at Prince Louis' royal christening.