52150216 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876

The O.C. star Rachel Bilson was all smiles with daughter Briar, 21 months, on Thursday (August 18). The Hart of Dixie alum, 34, toted her tot while leaving Pink Size Kids in Studio City, Calif.

Rocking a striped jumper, the adorable toddler accessorized with her favorite hat.

“Right now she won’t leave the house without her straw fedora hat. It’s her favorite,” Bilson recently told PEOPLE of her mini fashionista. “Her favorite thing to wear is my underwear on her head. She thinks it’s the best thing!”

It sounds like Briar – who Bilson raises with longtime love Hayden Christensen – has a flair for fashion.

“She has her own sense of style already,” Bilson shared. “She’s definitely on her way to being her own fashionista. She’s very into her shoes. Anytime we’re in a store, she has to try them all on, and she wants every pair!”

She added: “She won’t wear certain things. My brother got married recently and she had a flower girl dress. She literally would not even try it on until the day of the wedding. She refused! Then she miraculously put it on and loved it. She was a big poof ball.”

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52150212 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876
52150215 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876
52150216 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876
52150217 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876
52150223 Actress Rachel Bilson is seen leaving Pint Sized Kids in Studio City, California with her daughter Briar Christensen on August 18, 2016. Pint Sized Kids is owned by singer Gwen Stefani’s ex nanny Mindy Mann who had an affair with Gwen's now estranged husband, Gavin Rossdale. FameFlynet, Inc - Beverly Hills, CA, USA - +1 (310) 505-9876

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