PLYMOUTH TOWNSHIP, Mich. » A 15-year-old suburban Detroit girl accused of stabbing her younger brother as part of a plot to kill her family so that she could run off with a 23-year-old man was ordered held on $1 million bond Thursday.

The girl, who is facing adult charges of assault with intent to murder and conspiracy to commit murder in last Friday’s attack, wore a red jail jumpsuit at her hearing, which her parents attended.

Michael Rivera, who prosecutors and the girl’s parents describe as her boyfriend, was ordered held on $1 million bond Sunday. He faces the same charges as the girl, plus a felonious assault charge.

Prosecutors say the girl stabbed her brother in the throat and tried to stab her younger sister. The boy was treated at a hospital. Prosecutors contend that during the attack, Rivera was outside the girl’s Plymouth Township home sending text messages instructing her.

"He was using her to do his dirty work. She was under this man’s spell," the girl’s mother told reporters after the hearing.

The girl’s parents said she and Rivera were in a sexual relationship. The Associated Press isn’t naming the girl or her family members because prosecutors said they may file sex charges against Rivera, since the girl is a minor.

The parents said the girl met Rivera earlier this year through social media. They said they first learned about the relationship after their daughter ran away from home this summer.

"I think it was a big secret. I didn’t know about him," her mother said.

The couple said they adopted the girl and her two younger siblings from Poland when she was 4 1/2 years old. They said she had been receiving treatment for depression and ADHD.

"She’s never been violent in the past. We had no clue this was going to happen," her mother said. "She’s getting psychiatric counseling. She’s on medications. We’ve done everything in our power to help her."

Defense attorney Leslie Posner told reporters that the girl and her siblings were physically abused in Poland, eventually removed from their home in that country and later adopted by the Michigan family.

"They came from a very, very, very bad background," the lawyer said, referring to the abuse that allegedly came from the children’s biological parents. "They were locked in closets. They were beaten."

The parents in Michigan said they are supporting their daughter despite the charges. If released on bond, the judge said the girl can’t have any contact with her siblings and must wear a GPS monitor.

She made eye contact with her parents several times during the hearing.

"Your honor, we have a very strong bond with our daughter," her mother said.

Court records did not list a lawyer for Rivera on Thursday.

Preliminary hearings for both him and the girl are scheduled for Oct. 31.