The former Spice Girls star is eight months pregnant with her third child and recently played a prank on husband Stephen Belafonte and daughters Phoenix, 12, and Angel, four, when she pretended she was about to give birth and found their reactions hilarious.
She said: "I said to them the other day, 'Ooh I think I'm going into labour.' Stephen instantly turned white.
"Phoenix ran to get my bag and Angel asked, 'Is there gonna be blood?'
"All three went into complete panic mode. I'm going to have such a laugh watching them run around the delivery room like headless chickens."
The Australian 'X Factor' judge doesn't know the gender of her unborn baby, but says her elder daughter is hoping for a boy.
She said: "Phoenix is sick of pink tutus and Barbie dolls.
"Angel doesn't care as long as they can play dress-ups together – she just wants it to come out.
"I told both of them that I was going to be having a baby even before I got pregnant and they both gave me the go ahead but it must feel to Angel that I've been expecting forever."
