"It is such a happy and exciting time for Meghan", a source said, according to the New York Post.
She reportedly cancelled the yoga class she teaches at a senior citizens' centre, hired a dog walker and is having a friend put out her bins.
According to a report in the Sunday Times, there are plans afoot in the palace for the young couple to move overseas.
It seems punters are convinced the royal couple are expecting a girl and will name it after Prince Harry's late mother, Princess Diana.
"Royal punters are betting in their droves and they're clearly convinced that they know a baby Elizabeth is on the way".
The Duke and Duchess have now moved in to their new home, which has been renovated at an estimated cost of £3 million ($5.8m) to make it fit for their family of three and staff. "No decisions have been made about the future roles of the prince and duchess", a spokesman said.
If she does indeed have the baby on the 23rd, it would mean Meghan and Prince Harry's bub would share their birthday with another royal - Prince Louis - who was born on St George's Day previous year.
The grandmother-to-be is expected to stay with the Duke and Duchess at Frogmore for the next few weeks.
The baby will be seventh-in-line to the throne, and will be a dual UK-US citizen.