(CNN) At the age of 19, a young woman from Hoover, Alabama traveled to Syria to join ISIS -- the so-called "Islamic State."

Five years and three husbands later, she says she regrets what she did and is begging to return to the US.

In a recent handwritten note obtained by CNN from a family representative, Hoda Muthana writes , "When I left to Syria I was a naive, angry, and arrogant young woman. I thought that I understood my religious beliefs."

But after witnessing the devastation of war, including the death of two husbands, Muthana said she became disillusioned.

"During my years in Syria I would see and experience a way of life and the terrible effects of war which changed me. Seeing bloodshed up close changed me. Motherhood changed me. Seeing friends, children, and the men I married dying changed me," the now 24-year-old wrote.

"Seeing how different a society could be compared to the beloved America I was born and raised into changed me. Being where I was and seeing the (people) around me scared me because I realized I didn't want to be a part of this. My beliefs weren't the same as theirs."

CNN has not yet been able to speak with her directly.

Outspoken support

Once described as shy and reserved by a high school classmate, Muthana was fiercely outspoken in her support for jihad after joining ISIS. During the height of the self-declared caliphate, Muthana posted tweets calling for violence, according to the Program on Extremism at the George Washington University.

"Hoda was right in the mix for English language propagandists," said terror researcher Seamus Hughes. "We followed her for a number of years. She was a key node."

She demanded more Americans come to the self-proclaimed Caliphate and join the fight with ISIS.

Coalition jets hit ISIS positions in Susa, Syria, in January.

"Soooo many Aussies and Brits here, but where are the Americans, wake up u cowards," she posted in January 2015.

And under the name Umm Jihad, she encouraged attacks in the US, tweeting this exhortation in March 2015: "Go on drive-bys and spill all of their blood, or rent a big truck and drive all over them."

According to Mia Bloom, who tracks female jihadis at Georgia State University, "She was one advocating for extreme violence, especially against American military and servicemen."

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Regret

In a February 19 interview with ABC News, Muthana said she is now ashamed of those posts, and wishes she could take them back. She said she feels remorse and sorrow and regret, and begged to return home.

"I hope America doesn't think I'm a threat to them and I hope they can accept me," she told ABC.

But if she does end up returning to the US, it may not be on her own terms.

Hassan Shibly, head of Florida's Council on American-Islamic Relations and a representative for her family, said the family understands Muthana may be prosecuted, believes in the legal system, and asks only for due process.

The Justice Department did not comment on whether she would be extradited or prosecuted.

State Department spokesman Robert Palladino said Tuesday that he could not discuss her particular case, but said that for any ISIS members in Syria, the department's policy, "in this regard, would be to repatriate them -- and that's what we call on all countries to do."

Asked if ISIS members could be sent to the detention facility at Guantanamo Bay, Palladino would only say: "The US government is considering various alternative disposition options, for foreign terrorist fighters who cannot be repatriated."

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Kurdish refuge

According to Muthana, she ran away from ISIS a few weeks ago and headed for the Kurdish area in northern Syria, where she is now in a camp for the displaced with her 18-month-old son. In her note, she speaks of her son's future.

"In my quiet moments -- in between bombings, starvation, cold, and fear -- I would look at my beautiful little boy, and know that I didn't belong here, and neither did he," she wrote.

Only now does she "really understand how important the freedoms that we have in America are."

But Hughes, the researcher, has words of caution.

"Let's not put a rosy color on what she did," he said. "She joined a foreign terrorist organization."