Rachel Bilson was in Glendale, CA yesterday (October 6) doing some shopping at Target for Halloween gear.

The diminutive 28-year-old starlet was joined by her stepmother Heather Medway and half-sisters Hattie and Rosemary Bilson as she search for a costume and other items for the upcoming holiday of dressing up.

Meanwhile, after a seemingly endless break from work, Rachel has been cast in the 100th episode of How I Met Your Mother, parking debate over whether she may or may not be the famed mother.

The actress best known for her gig on The O.C. is set to play a love interest to Mosby (Josh Radnor).

Rachel will be joined by Tim Gunn of Project Runway fame as a “personal tailor/ fashion consultant as Barney tries to fix a major league ’suit catastrophe.’”