Being a royal lookalike is a precarious position at best, but Kate's number one impersonator, Heidi Agan has now started wearing a 'false bump' to give the impression she is pregnant.
The 32-year-old former waitress quit a low-paid job and has spent the past 10 months as the Duchess of Cambridge's double, earning up to $1000 a day.
Now she has had a "bump made in various sizes" to look as convincing as possible.
Heidi from Corby, Northamptonshire told the BBC: "As Kate grows I will too - to be authentic I thought it was important.
"It's difficult at the moment as she's not big enough yet to change her entire wardrobe so it's difficult to see how she's going to dress it."
She has also perfected the Duchess' mannerisms, how she stands - and even how she talks to William.
"Things like that are all very important if I want to be the best," she said.