A Virginia woman who tried to help a teenager join the Islamic State militant group and carry out a suicide bombing was sentenced Monday to 4½ years in federal prison for lying to the FBI about the plot.

Heather Elizabeth Coffman of Glen Allen said in a written statement read aloud by U.S. District Judge John A. Gibney that she now believes the terrorists she befriended on social media "are not what I thought them to be" and that she regrets actions that have separated her from her 7-year-old son.

Gibney said that while Americans are free to believe as they choose, Coffman crossed the line by recruiting for the Islamic State and lying to federal agents facing the daunting task of preventing terrorism.

"It's not like lying to your parents about who broke the lamp," Gibney said. "Her lies were blatant and just as two-faced as you can imagine."

Coffman, 30, pleaded guilty in February to making a materially false statement about an offense involving terrorism.

According to court papers, Coffman posted numerous messages on Facebook supporting the Islamic State and tried to help a teenager in Macedonia make arrangements to train and fight with the group in Syria. She had an online romance with the teen, describing him at times as her husband or fiance. The plan was for the teenager to carry out a suicide attack and die a martyr, but he backed out after their relationship soured.

Defense attorney Mary Elizabeth Maguire said that the Islamic State "has done a brilliant job of manipulating young people through social media" and that her client's immaturity made her a prime target.

"I think she never understood the gravity of what she was doing until it was too late," Maguire said.

She said a message Coffman sent to her Islamic State contact about her boyfriend's mission shows that she did not fully comprehend the gravity of the situation. The message said, "I kind of want him to be safe. LOL."

But Assistant U.S. Attorney Michael Gill said the serious nature of what Coffman was doing could not be ignored.

"She took several concrete steps," he said. "If they had come to fruition, people would have died."

In response to a question from the judge, Coffman acknowledged that she viewed videos online of Islamic State beheadings — a stark contrast to the woman who, according to relatives who wrote letters to the court, once bought mice at a pet store to save them from being fed to snakes.

After the FBI became aware of Coffman's online activities, an undercover agent who pretended to have a friend interested in joining the Islamic State contacted her and struck up a relationship. Coffman tried to make those arrangements as well. She denied her involvement when questioned by investigators.