Close family sources tell New Idea that the Oscar winner and her beloved hubby Keith Urban are trying for one last baby, and are desperately hoping it's a boy.
In fact, it's believed Nicole may even be pregnant, amid observations that she was spotted tenderly touching her stomach during last week's Golden Globes - and was also turning down all the champagne and alcohol.
'When the whole Big Little Lies crew were celebrating their win at the Golden Globes, there was champagne flowing freely - so it was very notable that Nicole was turning away all alcohol,' says an onlooker. 'She would accept a glass but it stayed full all night and no-one saw her take a sip.
'But what we did see was her touching her belly quite a bit - at one point, Keith even leaned over and touched her stomach lovingly. They were definitely acting like a expectant couple.'
It's no secret that Nicole and Keith love being parents, with the 50-year-old revealing that she's never given up her baby dream despite her age.
'I still have the faintest hope that something may happen to me this year,' she recently revealed to Mail On Sunday.
'Keith and I would love to have more babies. My grandmother gave birth to my mother at 49. I would be beyond happy and just welcome it with open arms.'
If her miracle baby dream comes true, sources say the busy actress is determined to stick with her filming schedule.
'It's early days yet, but Nicole wants to be prepared,' an insider says.
For the full story see this weeks issue of New Idea - out now!