Harlow Winter Kate Madden had a grand old time at the playground on Sunday — running through the grass with expectant mom Nicole Richie and digging in the sandbox — but when it was time to go, she wasn’t a happy camper!

The 15-month-old wanted to stay and play, but alas, the pair had to leave! At least Harlow will have a playmate soon — Nicole and dad Joel Madden expect a sibling for her in late August/early September.

See more family pics in their album, the Richie-Maddens.

Click below for a great belly shot of Nicole!