The Oscar winner and her son enjoy a day out in Pacific Palisades

By Alison Schwartz
Updated September 05, 2011 02:00 PM
Credit: Fame

Is she his plus-one?

Proud mom Sandra Bullock proved she isn’t the only one with social obligations this holiday weekend as she joined her baby boy Louis for a children’s party in Pacific Palisades, Los Angeles, on Sunday.

The Oscar winner, 47, kept one hand on her 20-month-old son – and the other on his sippy cup.