Rose Byrne expecting first baby with Bobby Cannavale

She's played a lawyer, a bridesmaid and a billionaire Bulgarian arms dealer, and now Rose Byrne is about to embrace her most challenging role.

Us Weekly has confirmed that the 36-year-old is expecting her first child with actor Bobby Cannavale, 45, her boyfriend of three years.

Rose and Bobby have co-starred together in three movies: Adult Beginners, Annie and Spy. Though private about their relationship, Bobby called her the "love of my life" while accepting his 2013 Emmy Award for Boardwalk Empire.

To be fair, Bobby's one true love has tackled the mum role before. She played a new one in the 2014 hit comedy Neighbours, but this will be her first shot at motherhood in real life.

The Aussie actress first set off pregnancy rumours in September when she was spotted with a baby bump on the set of Neighbours 2 in Atlanta. But was it real or just a movie prop?

Well, she still had the bump when she was seen walking through LAX on Thursday, so unless she's one of the most devoted Method actors in Hollywood, it's the real deal.

Congratulations to Rose and Bobby!

Here's the trailer for Adult Beginners, the couple's first film together. Oh yeah, she played a mum in that one too. Looks like Rose has already had lots of practice.