Nicole Richie Has Girls Day with Cameron Diaz Before Her Birthday!

Nicole Richie joins sister-in-law Cameron Diaz for a day out at the Montage Hotel on Monday (September 19) in Beverly Hills, Calif.

The actress and House of Harlow clothing designer celebrated her 35th birthday two days later. It looks like the gal pals got in a little early celebration.

PHOTOS: Check out the latest pics of Nicole Richie

Nicole recently opened up about how proud her famous father, Lionel Richie, is about her accomplishments. “[He] cries every time I’m with him,” she admitted to the Los Angeles Times. “I tell him, ‘Dad, I’m going to be 35. Let’s take it down a notch.’ But he’s very proud.”