She met an extremist online and wanted to marry him.
Nurse Shannon Maureen Conley, 19, from Colorado, in south-western US, planned to travel to Syria and join him.
The extremist, believed to be a 32-year-old Tunisian, belongs to the radical group Islamic State of Iraq and Syria (ISIS).
But Conley was arrested at Denver Airport as she was trying to board a flight to Turkey, the Mail Online reported.
Officials also seized propaganda about jihad (holy war) and Al-Qaeda from her luggage, along with CDs and DVDs labelled Anwar Al-Awlaki. The Al-Qaeda leader in Yemen was killed in 2011.
Conley was arrested in April but the court documents were revealed only on Wednesday.
She has been accused of providing material support to Islamist insurgents fighting the governments of Syria and Iraq, and of conspiring to commit an offence against the US, officials said.
Use training for war
She told agents she wanted to use her American military training from the US Army Explorers (a non-profit youth career exploration programme) to start a holy war abroad, even though she knew that it was illegal.
Her "legitimate targets of attack" included military facilities, government employees and public officials, the documents said.
She told investigators that she liked the idea of "guerrilla warfare because she could do it alone". She told the US Terrorism Task Force that she was a Muslim convert, CBS Denver reported.
"If they think I'm a terrorist, I'll give them something to think I am," she allegedly declared, referring to staffers at a local church where she had been spotted taking notes.
Federal Bureau of Investigation agents became aware of Conley's communication with the Tunisian and reached out to her and her parents John and Ana Conley, urging her not to go to Syria.
But according to a federal official, she could not be dissuaded. He said that Conley suffers from mental problems.
Mr Conley told agents that his daughter described jihad to him as a struggle to help the downtrodden, but she had been plagued by doubts about what was expected of her as a Muslim woman.
"She conceded her knowledge of Islam was based solely on her own research that she conducted on the Internet," court documents said.
Conley had met someone known to her as Y.M online, who said he wanted to marry her and help her join the ranks of extremists in Syria, the documents stated.
When Mr Conley found out that his daughter had a one-way ticket to Turkey for April 8, he contacted the federal agents.
"It's a difficult time for us," Mrs Conley told CNN on Wednesday.
This article was first published on JULY 4, 2014.
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