Melissa Rivers Melissa Rivers

Melissa Rivers has spoken out for the first time since her mother Joan's death.

On Wednesday, Rivers wrote a WhoSay post saying, "As my son Cooper and I mourn the loss of my mother, we want to thank everyone for the beautiful cards and flowers conveying heartfelt messages and condolences, which continue to arrive from around the world and through social media. My mother would have been overwhelmed by the scope and depth of the love that people have expressed for her. It is certainly helping to lift our spirits during this time. We are forever grateful for your kindness and support in continuing to honor my mother's legacy, and for remembering the joy and laughter that she brought to so many."

Joan Rivers: Hollywood remembers a comedy trailblazer

The Hollywood icon passed away earlier this month after she was rushed to the hospital when she stopped breathing during surgery on her vocal cords. Reports have since come out that Rivers' personal ear, nose and throat physician, who TMZ has identified as Dr. Gwen Korovin, was not authorized to practice at the clinic, Manhattan's Yorkville Endoscopy, where Rivers had gone in for a routine endoscopy. CNN has also reported that Yorkville's medical director, Dr. Lawrence Cohen, who has since resigned from his post, stepped aside to let Rivers' doctor — who snapped a selfie while Rivers was under anesthesia — perform a biopsy without her prior consent.

Joan Rivers: The 7 most endearing Aaecdotes from The Hollywood Reporter's oral history

On Friday, Rivers will make her first TV appearance since the passing when she joins Fashion Police's Giuliana RancicKelly Osbourne and George Kotsiopoulos for a 90-minute special honoring the comedienne. Prior to the special, E! is airing an all-day marathon of episodes including Joan's 80th birthday celebration and her final episode.