Amanda Holden has rushed to be by her sister Debbie's side after she was in a car accident earlier this week.
The Britain's Got Talent judge, 45, learned of the news of her sibling's involvement in the accident after attending Simon Cowell's birthday party on Wednesday and travelled down to Cornwall immediately.
Diving instructor Debbie, 44, is said to have been in a "critical but stable" condition in hospital, according to reports in The Sun.
A source told the newspaper that Amanda, who is very close to her sister, is "in absolute agony".
The source added: "She immediately travelled to Cornwall to be with Debbie.
"It's been a very difficult 48 hours and the whole family have been pulling together and trying to keep positive.
"Amanda is very close to her sister. They're only a year apart and there's something about them together which is really special. Amanda's still with her in hospital."
They added that Amanda "can't believe this has happened".
The sisters are said to have become very close in recent years after they endured a difficult relationship as children while growing up with their father Frank.