Jennifer Garner is a busy mom of three, wife to hot Ben Affleck, an accomplished actress — and she's turning 40 today! We're honoring the star with a look back at her sweet smile and those adorable dimples. Jennifer just gave birth to her first son, Samuel, making 6-year-old Violet and 3-year-old Seraphina big sisters. Jen's marking her milestone day with husband Ben and their children, and we're celebrating with a look back at 40 photos that capture her bright smile, gorgeous family, and fantastic career. Click through to see Jen's bright moments.