What are royal sister-in-laws for!
As it is the Duchess of Sussex's first child, "Kate is going all out to make it extra special - a truly unforgettable day," a palace source told the US publication.
"She's a complete perfectionist and has already begun planning the celebration months in advance.
"Duchess Kate considered having the shower at Soho Farmhouse, but thinks it'll be easier to host it at her Kensington Palace apartment."
Calling their bond "togetherness at its finest", the 36-year-old mum-of-three has been Meghan's rock during the pregnancy.
According to Life & Style, Meghan's been turning to Kate for all kinds of baby advice.
"It'll mean the world to Meghan - and Prince Harry - once they find out that Kate's gone out of her way to organise the show."
According to the royal insider, "it'll be a daytime event and guests, including Meghan's pals Jessica Mulroney, Priyanka Chopra, Serena Williams and Amal Clooney, will be treated to an American-style feast."
Kate wants "Meghan and all her friends from across the pond to feel right at home on the big day."