Watts told Channel 7 that being a mother is a 'powerful thing' and that she feels 'weird' when Alexander is away from her.
"It's a very powerful thing, I'm still finding it just so bizarre that this little thing came out of me," News.co.au quoted Watts, as telling the Channel.
"He's just a joy, a complete joy, all those cliches are true.
"He just moves me every day. It's weird being away from him, I feel like a piece of my body is missing," she added.
The 38-year-old actress hopes to bring her baby to Australia soon.
"I hope to take him for Christmas to show the rellies," Watts said.