The Scottish songbird who finished second in the "Britain's Got Talent" competition landed in a London hospital on Monday night after suffering what one of her brothers described as severe anxiety.
Show judge Amanda Holden and Max Clifford, who represents Cowell, both said Boyle should recover her equilibrium fairly quickly now that she is getting treatment.
Holden said Boyle does not have any underlying mental problems.
Clifford said Cowell, the mogul who helped create the show, plans to work with Boyle after she is better to make sure her career gets off to a good start.
"She is recovering well," Clifford told The Associated Press after speaking by telephone to Boyle's two brothers.
"They are saying they weren't surprised by what happened, due to the speed of everything that happened, with her getting worldwide fame in seconds. Provided she's given a few days and then allowed to be as normal as possible, she should be fine. All she wants to do is sing."
The cut-throat show continued to draw criticism in the British press today for its cavalier attitude toward the well-being of participants, and Britain's independent Ofcom agency, which handles complaints about broadcasting, said an investigation is possible.
But attention shifted to speculation about Boyle's future, with most predicting commercial success but some saying she would have a hard time attracting a paying audience.
Clifford, who has represented many of Britain's biggest stars, said there is little doubt that there is a public appetite for Boyle.
He said her mental stability should not be an impediment provided she is surrounded by people she trusts, either her brothers or close friends from Blackburn, Scotland, her longtime home.
"It shouldn't be too difficult to get it under control," he said. "She's going to have potentially huge album sales, particularly in America. Americans absolutely love her. Everyone wants her on their show singing. That gives her massive potential, and Simon will make sure she has the best songs and the best productions."
Her brothers have also said she wants to continue her singing career despite the problems in the last few days. It is not clear yet whether Boyle will be well enough to take part in a 17-show "Britain's Got Talent" concert tour set to begin on June 12.
Organizers said they expected Boyle to perform along with the other nine finalists, but no final decision has been made.
Promoters believe that if she recovers fully her real money-making potential will be realized in the United States, where she has become a YouTube sensation and been featured on TV shows hosted by Oprah Winfrey and Larry King.
"I don't think this collapse would hurt her, especially in America, where they love redemption stories," said concert promoter and publicist Gerry Lyesight.
"As long as she recovers fully, she goes back to where she was. You have to assume there's an audience since she got over 100 million YouTube hits. Even if only 1 percent of them are fans, that's still 1 million people."
He said his choice would be to present Boyle in smaller venues seating 2000 to 3000 fans rather than place her in football stadiums, where she might feel intimidated by the size and scope of the crowd.
"That's what I would do, but it may be they are going for the fast buck," he said.
Some experts, however, believe Boyle's success on a free television show will not easily translate into a paying audience once she turns pro.
"There are questions of if she is a flawed jewel and it will cost too much to polish her up," said Mark Borkowski, a publicist and author.
"In the Internet world you can explode overnight, and she can spread with Twitter and YouTube, but that's not going to make her money. The question is whether people will pay the dollar, or two dollars, or 10 dollars or more to see her perform, and I don't think they will."
