Jennifer Garner had a child-friendly birthday party on Saturday (17.04.10).

The actress - who has two daughters, four-year-old Violet, and 15-month-old Seraphina with husband Ben Affleck - turned 38 at the weekend and decided to mark the occasion with an afternoon bash at her Los Angeles home, inviting celebrity friends such as Reese Witherspoon and Tobey Maguire and their kids.

A source said: "Jen wanted everyone to feel like they could bring their kids, so she didn't want to have it at night. Even though there were a bunch of celebs there, it didn't feel like a Hollywood party at all. It just seemed like some friends getting together to celebrate a birthday."

The 'Valentine's Day' star wanted a low-key gathering so guests turned up in casual attire with their families.

Tobey - who brought along his three-year-old daughter Ruby - looked "all messy" and was "wearing a T-shirt and jeans", while Reese wore shorts, sneakers and a straw hat and had "hardly a stitch of make-up on".

'Juno' actor Jason Bateman also attended the party with his three-year-old daughter Francesca, who quickly ran off to play with Jennifer's daughter.

The source added: "Frankie and Violet are pals, so they played in Violet's room."

Jennifer started her birthday celebrations on Friday (16.04.10) as she was spotted being given a pedicure with Violet in the afternoon.