The baby girls were born on Thursday night, and a source confirmed to HELLO! that "the whole family are over the moon and all doing well".
Julia Bradbury announced her pregnancy in December
Last December Julia revealed that she was "completely overjoyed" about her pregnancy. She said: "The prospect of having two for one is just incredible.
"Starting later in life having children, I didn't ever think I'd have a big family. Zeph was the unexpected miracle and I was thrilled and happy to have him. It's taken a long time to get to this stage so the prospect of going from one to three is utterly amazing."
In the interview, Julia revealed that the babies were conceived on her fifth round of IVF treatment. And she says that given her age, she is being very cautious during the pregnancy. "I am slightly guarded and I'm not taking anything for granted," she said. "This whole process is very much about milestones – getting to the next stage – so it's quite a rollercoaster. We've got to be ultra, ultra careful, really cautious and try to stay as healthy, calm and comfortable as possible."
Julia and her partner Gerard Cunningham also have a three-year-old son
And she said she was "gobsmacked" to discover she was expecting twins. "It's not an impossibility when you go through IVF. But when we found out at the first scan, we were gobsmacked. It was like 'Okay, deep breath'."
Julia also says that her partner Gerard has been "incredibly supportive", adding: "He knows what I've been going through and said if he could do it, he would have.
"But he's equally passionate about siblings for Zeph – he's one of eight. There was never a moment when he said, 'Oh God, it's twins.' He was like, 'Brilliant.' If he could squeeze in four or more, he'd be happy," she says. "Octomum!"