Sarah Michelle Gellar has shared an uplifting health update with fans, revealing she has tested negative for coronavirus.The Buffy The Vampire Slayer actress posted a selfie with her friend Benita, adding: "Friends that COVID test together stay healthy together."She also added that she "tested negative".MORE: Sarah Michelle Gellar's bathroom inside $6 million mansion will blow your mindWATCH: Sarah Michelle Gellar's daughter shows off impressive trampolining skillsThe star wore a khaki-colored