The teenager, who cannot be named, moved in with Lee Kaplan of Bucks County when she was 14, and gave birth to their first child at 15. Their second arrived two years later.
Kaplan has been charged with statutory sexual assault, corruption of minors, aggravated indecent assault, indecent assault and unlawful contact with a minor.
According to reports by Fox News, the young girl was “gifted” to Kaplan by her parents, who are also facing charges, in return for financial support.
She was discovered, along with nine of her sisters, in Kaplan’s home earlier this year.
"They were living down in the basement, they were hiding in the chicken coop," said Robert Hoopes, Lower Southampton Director for Public Safety during a press conference according to 6ABC.
"They're Amish, and they have a different way of life I would guess."
Police have revealed they investigated Kaplan after a tip off from a neighbour who spotted a number of the girls looking “unhappy and sad”.
"I just wasn't going to let go,” Jen Betz told 6ABC. “I saw a couple girls last week standing in the driveway. They just looked unhappy and sad ... and I've been telling my husband for years something isn't right, something isn't right.”
According to TNS, there was no identification for the girls found in the house, nor any evidence they had been to doctors or schools. When the 18 year old was asked who delivered her children, she seemed confused. “What do you mean by that?” she asked, according to the Sydney Morning Herald.
The girls are currently being cared for by the Bucks County Children and Youth Services.