Charlotte Casiraghiis getting ready to welcome Monaco’s newest royal!

The eldest granddaughter ofGrace Kelly, who isexpecting a child with fiancé Dimitri Rassam, was spotted out on a sunny day in Cap Ferret, France. The mom-to-be’s growing belly was on display in a chic one-piece bathing suit, which she wore with a matching wide-brimmed hat.

The couple have been staying close to Monaco on a Mediterranean cruise, spotted in St. Tropez as well as sailing to the Italian island of Pantelleria, where Rassam’s mother, glamorous French actress and former Bond girlCarole Bouquet, has a vineyard.

A source previously told PEOPLE that Charlotte is “due late this summer, early September,” and friends suggest that the couple will marry in the spring.

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Charlotte Casiraghi Enjoys Vacation In Cap Ferret

Charlotte Casiraghi Enjoys Vacation In Cap Ferret

The child will be the seventh grandchild for Princess Caroline (the 62-year-old royal’s clan haswelcomed two additions since April) and the second grandchild for Dimitri’s mother.

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Day 3 - Global Champions Tour of Monaco 2018

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The couple are graduates of the Sorbonne University in Paris, and each have children from previous relationships: Charlotte has a 4-year old son, Raphael, with comedian Gad Elmaleh, and Dimitri has a daughter from his marriage to model Masha Novoselova.

source: people.com