Roksana Sikorski in court.

By JOANNA ROBIN.

It’s every parent’s worst nightmare, but a Michigan couple are standing by their adopted daughter even though she was planning to kill them.

Roksana Sikorski, 15, stabbed her brother in the neck and revealed to police that she and her 23-year-old boyfriend had been plotting to kill her mum and dad after they accused him of statutory rape, NBC News reported.

Sikorski’s lawyer told a Detroit court that the teenager had been an ideal child who only began acting out in adolescence.

Roksana, who is on medication for attention deficit and hyper activity disorder and post-traumatic stress, became increasingly secretive and erratic after meeting her boyfriend Michael Rivera on Facebook, her lawyer said.

She was caught by police after trying to slit her younger brother’s throat and confessed to the plot to kill her parents.

Laurene and Jeff Sikorski have defended their daughter and blamed boyfriend Rivera for the attack.

“I think she just thought this guy loved her and she wanted to do whatever he told her, and she was very vulnerable, and she has a mental disorder and she needs help,” her mother said.

“I want to make sure she gets help.”

Jeff and Laurene Sikorski stuck by their daughter in court.

The couple adopted the girl and her younger brother and sister from an abusive home in Poland where the children had “suffered horribly,” the girl’s lawyer Laurie Poser told the court.

Michael Rivera

According to prosecutors, on the night that the attack happened Rivera was outside the family’s home, texting instructions to his under-aged girlfriend.

“He was telling her how to cut the brother’s jugular vein,” the lawyer said.

Roksana stabbed her 12-year-old brother in the throat and attacked her sister before running away to her boyfriend’s house where police found her.

The teenager was charged as an adult and could face life in prison, but her lawyer is trying separate her case from Rivera’s.

“They’re trying to make them look like Bonnie and Clyde,” she said.

Watch the story unfold, here: