Joel Madden, Nicole Richie and daughter Harlow
12/18/2008 AT 04:00 PM EST
, "having a blast" during a family shopping outing at L.A.'s outdoor mall The Grove with daughter Harlow
, 11 months, and Joel Madden
. "Nicole was holding Harlow and Joel was pushing the empty stroller," an onlooker says. The threesome shopped at Barneys New York, but also stopped to watch the water fountain show. "Harlow was laughing and they were helping her stand up and dance on the ledge," the onlooker adds.