The actress, 46, accompanied by her husband Eric Dane, 44, appeared to be having a happy time at the annual event -- but she and her family members are still dealing with the aftermath of Rachel's passing.
Gayheart's sister, 38, died in August after being incarcerated in Kentucky and suffering symptoms of pneumonia while in jail, as RadarOnline.com has exclusively reported.
She later died at the Hazard ARH Medical Center Hospital in Kentucky, Lonnie Brewer, jail administrator for the Perry County jail, confirmed to Radar.
A Perry County Coroner's representative told Radar on Sunday, Sept. 3 that Rachel's autopsy has not yet been completed and the results will likely not come in "for several months."
Her medical files and treatment have all been subpoenaed as police conduct a thorough investigation, as Radar has previously noted.
Star Magazine reported in reported in 2014 that Rachel had issues with drugs in the past and had been arrested three times.
"Rachel has had problems with drugs," their father, Curtis Gayheart, previously told Star.
Rebecca shocked many when she shared a picture of herself celebrating her 46th birthday with her two girls, just days after her sister tragically died in the hospital.
But Rebecca and her Grey's Anatomy star husband Dane, who has battled depression, weathered other scandals.
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