Sarah Michelle Gellar is focusing on her physical and mental well-being while mourning the loss of her former costar Michelle Trachtenberg. "It's true what they say … girlfriends and exercise are good for your mental health,

They’ll always be the Summers sisters. Sarah Michelle Gellar and Michelle Trachtenberg became close friends while playing Buffy and Dawn Summers, respectively, on “Buffy the Vampire Slayer” — a tight bond that lasted until Trachtenberg’s tragic death at age 39.