Nicole Richie worries she isn't fun anymore

Nicole Richie worries she isn't as fun as she used to be.

The 26-year-old 'Simple Life' star, who gave birth to her first child -- Harlow -- on January 11, says becoming a mom has made her want to settle down and stop partying.

Nicole said: "Sometimes I will think to myself, 'I used to be fun! What if I'm not fun anymore?' But I am who I am. I am still fun, just not in that way."

Richie's rocker fiancé Joel Madden insists the couple's lives have "mellowed" since they became parents for the first time.

Joel said: "It's not like we had to give up so much because of the baby. It's not like the baby made me sober. Nicole got pregnant, and we were like, 'Great, let's do this!'

"We have a very mellow life compared to two or three years ago - but we wouldn't have it any other way. We are very comfortable with this new chapter in our lives."