This is the pregnancy tip Pippa Middleton got from Serena Williams

And it makes total sense

If we're not celebrating royal babies, we're celebrating royal relatives' babies.

Case in point? The world was delighted when news broke that Pippa Middleton is pregnant with her first child.

The 34-year-old is expecting a baby with husband James Matthews and is reportedly due in October, having shared news of her pregnancy just before Prince Louis' birth.

Fortunately, unlike her sister Kate, she has not suffered with the condition hyperemesis gravidarum, the extreme morning sickness condition that affects just one per cent of pregnant women.

Pippa has now shared one of the ways she's maintaining good health during her pregnancy – and there's a surprising celebrity influence behind it.

The Duchess of Cambridge's sister recently revealed in her Waitrose Kitchen column that she's been taking pointers from tennis champ Serena Williams.

‘I’ve been a tennis fan since childhood, as a player and spectator, and have been keen to continue playing safely throughout my pregnancy,' she wrote.

'Take Serena Williams. She famously proved that women can play a high level of tennis from two months (when she won the 2017 Australian Open) up to eight months.

‘Few of us can relate to this elite excellence, but if you’re a healthy, well-trained player with an uncomplicated pregnancy there’s no reason why you can’t continue a good level of tennis,' she added.

‘I’ve noticed my body change, but through exercise, I feel it’s being strengthened.’

We can't wait to hear news that George, Charlotte and Louis' first cousin has finally arrived – any thoughts on a name?