Nicole Richie on baby Harlow: "she's doing great"

New parents Nicole Richie and Joel Madden can't stop gushing about their one-month-old daughter, Harlow Winter Kate Madden.

"She's doing great!" Richie, 26, said at the opening of the Eli Broad Contemporary Art Museum in L.A. last night.

"Really great, thank you!" added the former 'Simple Life' star, who looked slim and rested in a pale-colored dress.

Good Charlotte frontman Joel Madden, 28, then gushed to Us Weekly magazine: "Yeah, she's good!"

The museum opening was just the first stop on the pair's date night.

Afterward, they attended Clive Davis' Pre-Grammy party at the Beverly Hilton Hotel — but didn't stay for long.

"We have to get home!" Madden was overheard telling a friend at 11:40 p.m. "She [Harlow] only sleeps three hours at a time. She's with Grandma now, but if she wakes up..."