Toni Street has revealed how she explained her surrogacy to her two daughters

Telling your kids that they're about to get a younger sibling can be tricky at the best of times.

But having to explain that their baby brother will be born via surrogate has made for an added twist for Toni Street to navigate.

Street - who announced she will have her third child with the help of her best friend Sophie Braggins - says she decided to "keep it really simple" when breaking the news to her daughters, Juliette, 5, and Mackenzie, 2.

"What I did say to them was: 'Mum's having a baby. You know how I got really, really sick last time and was in hospital for weeks?" she said referring to her auto-immune disease Churg-Strauss, "Well, we don't want that to happen again.

"'So I'm actually just going to make the baby and I'm going to give it to Aunty Will' - which is Sophie, my surrogate - 'and she's going to grow it for us'", Street explained on air today.

And how did her daughters react?

"They just went, 'Aw yeah'. And that was it!" Street reveals.

"They've just taken it as fact and they're not even questioning it at all ... They're very positive about it."

However, Street says getting them to keep it a secret actually turned out to be the hard part.

"Maybe I was being overly trusting of a 2-year-old and a 5-year-old," Street laughed before revealing how her youngest ended up running around her creche yelling "It's a boy!"

"Word of warning: Don't tell a 2-year-old anything you don't want the world to know about."