Nicole Richie is a "completely dedicated mom" according to Joel Madden.

The Good Charlotte rocker - who has an eight-month-old daughter Harlow with the star - is constantly surprised by Nicole's parenting ability.

He said: "Nicole is completely dedicated. I do whatever she tells me to do. I'm cool with that. She's really good with the baby. I'm really good with finances. All of Harlow's education and all that stuff, I already have planned."

Nicole revealed having a baby has changed her life, saying: "I think my sense of self is still the same. But I don't do things, we do things. I work around her."

The 27-year-old beauty says her young child is already exhibiting characteristics of both her parents.

Nicole added: "Harlow's a delicate soul. She studies people. She's very coy. People say that she and I make the same expressions. But everyone says she looks like Joel."

The couple also admitted they are considering extending their brood.

Joel told People magazine: "If it could be as easy as Harlow, then sure we will have more kids."