Susan Boyle’s brother has spoken of his worry for his famous sister and claimed that although she may be known worldwide, he fears that she is ‘the loneliest woman in the world.’

Susan insisted today that she was ‘happy and doing fine,’ however her brother believes that her assertions couldn’t be further from the truth.

Gerry told The People:

“I worry Susan will become totally consumed by fame and lose touch with reality.

“If that happens the lid could come off at any moment.

“I need to protect her because she is still so insecure and vulnerable. Her family are her only anchor. Without us she could be cut adrift.”

On Susan’s reaction to the rapturous response she received from fans in America this week, Gerry said:

“Susan said she was in great spirits but it was clear she had become totally overwhelmed by the reaction to her by the American public.

“I kept asking her ‘Are you calm, are you happy?’ and Susan replied that she’s where she wants to be, which reassured me.

“She said it was the patchwork quilt presented to her which had been stitched together by hundreds of people from 28 countries which set her off. When I asked about the pictures of her sucking her thumb she said she didn’t even realise she was doing it.

“I’ve not seen her do that since she was a child but perhaps it was her way of comforting herself.

“I told Susan she needed to kick back quietly for a few days and spent time carefully telling her everyone loved her especially her family and of course her beloved cat Pebbles which she always asks about.”

What Susan’s brother worries most about, is what will happen to Susan if the fame and recognition all comes to an end.

He said: “What worries me is that Susan is aware she can be the hottest thing around today and be gone tomorrow.

“She pours out her heart to me all the time and can get into a groove of feeling sorry for herself. I spoke to Susan before she flew out to America and she knew this was really the start of the big time.

“But that also brings its problems if her head isn’t in the right place. The thumb-sucking and sobbing wasn’t a sign she’s cracking up but it’s alarming. She is so different to everyone else and the least thing can send her into a pit of depression.”