A mother in small town America was last night struggling to understand how her daughter had been swept up in an alleged international plot to kill a Swedish cartoonist who angered Muslims by depicting the Prophet Mohammed as a dog.

The case of Jamie Paulin-Ramirez, a trainee nurse from Leadville in Colorado, who was arrested in Ireland last week, comes on the heels of charges against another American woman, Colleen LaRose from Philadelphia, who called herself "Jihad Jane".

Their twin stories are forcing the US to confront the reality of home-grown fundamentalism, and the ease with which individuals can be sucked into an online network of intolerance and violent conspiracy.

And in Leadville over the weekend, the parents of Ms Paulin-Ramirez, 31, were in no doubt that – despite the absence of official confirmation from investigating authorities in the US or Ireland – it was "Jihad Jane" who had recruited their daughter into the alleged plot to murder Lars Vilks.

"These terrorists came into my home through the internet, uninvited, and have ripped my family apart," Christine Mott told reporters.

Last night, it appeared that Ms Paulin-Ramirez had been released from custody in Ireland, and her family were seeking news of her six-year-old son with whom she travelled across the Atlantic last year, a few months after converting to Islam. The Algerian man she travelled to marry was believed to be among three of the seven detainees still in custody.

Growing up, Ms Paulin-Ramirez was "the kid in the class everyone picked on and made fun of," Ms Mott told the Associated Press. She was married three times before she left for Ireland, and her first husband used to beat her, she said. Her second husband, the six-year-old's father, was an illegal immigrant from Mexico and was deported years ago.

"I'd yell at her, 'Get off the computer, do something with your son'," Mrs Mott said, adding that her increasing extremism led to her estrangement from the family. "We were enemies. We couldn't even speak to each other. She lost her mind." The Algerian man was Ms LaRose's "main contact" in Europe, Ms Paulin-Ramirez's parents claimed. They had been able to speak regularly with their grandson, Christian, on the phone until the arrest last Tuesday, and had become increasingly angry with their daughter as he was taught how "Christians are going to burn in hellfire". His mother had changed his name to Walid after her conversion.

The images of America's latest homegrown Islamist terror suspects have shaken widely-held beliefs: both Ms Paulin-Ramirez and Ms LaRose are the picture of the all-American blonde. According to prosecutors, Ms LaRose said she thought her blonde hair and blue eyes would help her move freely in Sweden to carry out an attack.