Katherine Heigl wants "more children".

Katherine Heigl

Katherine Heigl

The 38-year-old actress may have only given birth to her son Joshua Bishop Kelley Jr - whom she shares with her husband Josh Kelley - last month, but she is already looking forward to expanding her family even further as she says she would "get pregnant again" but is also "very inspired" by the idea of adoption.

Katherine - who has already adopted two daughters, Nancy, eight, and Adalaide, four, with the 37-year-old musician - said: "I still want more children. I'd get pregnant again, and I still am very inspired by adoption. I also have been thinking a lot about fostering."

And the 'Knocked Up' actress has praised her two daughters for being "very smart" and full of "self-esteem".

She added: "Nancy Lee is my very, very smart, very compassionate, very big-hearted little gal. She's totally Mommy's little helper and loves being the big sister.

"Adalaide has so much just inherent self-esteem, which I am so proud of and so grateful for. When you're raising girls, you want them to be confident and you want them to love who they are. With Adalaide, I'm not gonna have any problems with that."

Meanwhile the 'Grey's Anatomy' star says she's finally found balance in her life, and loves being able to "turn off" her life as an actress when she's at home with her family.

She told the latest issue of PEOPLE magazine: "I know I'm always going to want to act and be a storyteller. I can do that and then do what I have to to promote that, like making sure [I] look great, having a cute outfit, losing that baby weight.

"But when that is done, [I can] go home and completely turn that part of my life off. And that, to me, is very necessary."