Authorities said the case shows how terror groups are looking to recruit Americans - even suburban women - to carry out their goals.
A federal indictment charges that Colleen R. LaRose agreed to kill a Swedish citizen on orders from the unnamed terrorists and traveled to Europe to carry out the killing. It doesn't say whether the Swede was killed, but LaRose was not charged with murder.
U.S. Attorney Michael Levy told The Associated Press the indictment doesn't link LaRose, a U.S. citizen who moved to Europe in August 2009, to any organized terror groups.
Authorities describe LaRose as in her 40s and from Montgomery County. They say she called herself JihadJane in a YouTube video in which she said she was "desperate to do something somehow to help" ease the suffering of Muslims. According to the indictment, she agreed to obtain residency in a European country and marry one of the terrorists to enable him to live there.
"Today's indictment, which alleges that a woman from suburban America agreed to carry out murder overseas and to provide material support to terrorists, underscores the evolving nature of the threat we face," said David Kris, assistant attorney general for national security.
LaRose also agreed to provide her co-conspirators in Asia and Europe financial and passport help, the indictment charged.
LaRose has been in federal custody since her Oct. 15 arrest in Philadelphia, authorities said. She had an initial court appearance the next day but didn't enter a plea. The two federal public defenders representing her did not immediately return telephone messages seeking comment Tuesday.