Rebecca Gayheart is honoring her eldest daughter, Billie, days after Eric Dane's death. "Happy sweet 16 to the sweetest girl - mommy loves you to the moon and back unconditionally forever and ever," Gayheart, 54, wrote via her Instagram Story on Tuesday, March 3. Alongside the message, Gayheart shared a throwback photo of daughter Billie holding ice cream. She paired the image with Kina Grannis' "You Are My Sunshine." Gayheart also shared a slideshow of pictures of Billie through the years, including an image of her with Dane, alongside Fleetwood Mac's "Landslide.