WHITE PLAINS — A disgraced Olympian, Marion Jones, whose speed and smile made her an international superstar until steroid use led to her downfall, was sentenced today to six months in prison for lying to investigators about performance-enhancing drugs and a check-fraud scam.

The judge sentenced Jones despite her plea that he not separate her from two boys, “even for a short period of time.”

“I ask you to be as merciful as a human being can be,” she said. Jones cried on the shoulder of her husband after learning her fate.

The sentence completes a stunning fall for a woman who was once the most celebrated female athlete in the world. A runner and long jumper, she won three gold and two bronze medals at the 2000 Olympics in Sydney.

But in October, Jones told the judge that she lied to a federal investigator in November 2003 when she denied using performance-enhancing drugs. She said she took steroids “several times before the Sydney Olympics and continued using it after.”

Jones had hoped to avoid prison, but U.S. District Judge Kenneth Karas said he was giving her six months — the maximum called for under her plea deal — “because of the need for general deterrence and the need to promote respect for the law.”

As she pleaded for mercy, Jones talked at length about her children, including the infant son she is still nursing.

“My passion in life has always been my family,” she said. “I know the day is quickly approaching when my boys ask me about these current events. I intend to be honest and forthright … and guide them into not making the same mistakes.”

The judge said he believed a message needed to be sent to athletes who have abused drugs and as a result, have overlooked the values of “hard work, dedication, teamwork, and sportsmanship.”

“Athletes in society have an elevated status, they entertain, they inspire, and perhaps, most important, they serve as role models,” he said.

Jones’s lawyers told the judge that Jones has been punished enough and should have been sentenced only to probation, or perhaps be confined to her home. Prosecutors did not insist on prison time either, saying any sentence between probation and six months would be fair.

Jones, 31, also admitted lying about her knowledge of the involvement of the father of her son Monty, Tim Montgomery, in a scheme to cash millions of dollars worth of stolen or forged checks. Montgomery and several others have been convicted in that scam. They include former an Olympic champion, Steve Riddick, who was to be sentenced later today.

After her guilty pleas, Jones was released pending her sentencing; she was ordered today to surrender on March 11 to begin her term.

After her guilty plea last year, she made an apologetic and teary-eyed statement outside court, saying, “It’s with a great amount of shame that I stand before you and tell you that I have betrayed your trust.”

“I have been dishonest, and you have the right to be angry with me,” she added. “I have let (my family) down. I have let my country down, and I have let myself down. … I want to ask for your forgiveness for my actions, and I hope you can find it in your heart to forgive me.”

Jones returned her Olympic medals — golds in the 100 meters, 200 meters and 1,600-meter relay and bronzes in the long jump and 400-meter relay — even before the International Olympic Committee ordered her to do so and wiped her records from the books.

Jones was among the athletes who testified before a grand jury in 2003 in an investigation into BALCO, a lab at the center of the steroids scandal in professional sports. In 2004, she said, “I have never, ever used performance-enhancing drugs.” She also sued the BALCO founder, Victor Conte, after he repeatedly accused Jones of using performance-enhancing drugs and said he watched her inject herself.

But on the day she pleaded guilty, prosecutors said a 2003 search warrant at BALCO uncovered ledgers, purchases, doping calendars, and various blood-test results connected to Jones and a former coach, Trevor Graham.