Fiona Lowe, the 13-year-old daughter of actor Chad Lowe, died in hospital on Tuesday, 29 September, according to County of Los Angeles Medical Examiner records seen by Page Six.
Her family confirmed the news in an emotional statement released on Tuesday, describing the loss as "devastating" and requesting "prayers and privacy at this time."
Family's tribute to Fiona
In the statement, her relatives said: "We are deeply heartbroken by the loss of our beloved Fiona. She was a loving young girl who was smart, creative and loved to dance."
They added: "She was adored by her sisters, and she was deeply loved by her parents. In fact, she was the light of our lives."
Rob Lowe by Chad's side
Sources told Naughty But Nice that Rob Lowe immediately "dropped everything" to be with Chad following the news. An insider said: "Chad is his little brother, and the second he heard, Hollywood stopped mattering. There was nowhere else Rob was going to be except by Chad's side."
A separate source added: "Rob knows there are no words that can fix this. He can't take away Chad's grief. What he can do is be present, protect his brother and make absolutely certain he never has to face this alone. Right now, he's simply a big brother helping hold his family together."
Support from friends and family
People magazine reported that Rob, alongside close friends, have "rallied around" Chad and his wife, producer Kim Painter. They said: "Everyone's heartbroken. Right now, the focus is on being there for them in any way they can."
The family's statement following Fiona's death concluded: "If you or someone you know is struggling with mental health, please reach out to the 988 Suicide and Crisis Lifeline by calling or texting 988."