New mum Kate Hudson is eager to "pump out" another child so her boyfriend can have a son of his own.

The Almost Famous star welcomed daughter Rani, her first child with Danny Fujikawa, in October (18), with the little girl joining big brothers Ryder, 15, and Bingham, seven - Kate's kids from previous relationships.

The actress can't stop gushing about the new addition to her family, particularly because it wasn't too long ago that she thought she would have to give up on her dream of having more children.

"I always thought I'd have four to six kids, that was when I was really little. But when you come from a big family, I think you (either) don't want kids, or you want a lot of kids, so I always thought I'd have (more)," she told U.S. breakfast show Today.

"And then at one point I thought, 'Well, maybe I'm done,' and then I met Danny and it was like, 'Alright, well..., I gotta pump 'em out!'"

Kate, who began dating Danny in early 2017, is now hoping another pregnancy will be on the cards in her not-too-distant future.

Asked if she'd like more children, the 39 year old said, "If it works out that way. He (Danny) needs a boy, right? His own boy."

The mother-of-three reveals her two sons have quickly fallen in love with their baby sister, but Ryder recently made her realise just how big an age difference there was between himself and the tot.

"It's also really interesting... with 15 years and a newborn, it's a completely different generation," Kate mused. "And my son (Ryder) looked at me and said, 'Mum, when I'm 30, she's gonna be just turning 16.'

"That's wild that I'll have a 30-year-old kid and a child in high school!"