A Rohnert Park mother charged with manslaughter in an early morning crash that killed her two daughters had been drinking the day before and had methamphetamine in her system, a prosecutor said Friday.

Alejandra Hernandez-Ruiz, 27, also had been deemed a negligent driver by the state for a history of erratic behavior behind the wheel, Deputy District Attorney Laura Passaglia told Judge Jamie Thistlethwaite before a packed Santa Rosa courtroom.

It was the first time since Hernandez-Ruiz’s arrest last Friday that prosecutors released details about why they charged the woman more than a year after the crash with two counts of vehicular manslaughter with gross negligence, child endangerment and driving on a suspended license.

Still, the judge agreed to release her from jail on electronic home confinement so she could receive treatment for aggressive cervical cancer, which she was diagnosed with after the crash. Thistlethwaite said she would be subjected to drug and alcohol testing and ordered her not to drive.

“If you do you will be back in custody so soon,” the judge said.

Family members who attended the hearing supported her release.

“We are glad they are putting her health care first,” said Norma Gonzalez, a sister-in-law.

Hernandez-Ruiz’s lawyer said there was no evidence the methamphetamine played any role in the crash. Attorney Izaak Schwaiger said two Department of Justice lab testers agreed she was not impaired. Also, his client underwent a battery of sobriety tests right after the crash that determined she was not under the influence, he said.

“My review is that the charges are not supported,” he said.

Prosecutors have not charged Hernandez-Ruiz with driving while intoxicated. They had previously said the allegations were based on “the totality of her conduct while driving.”

Passaglia declined to comment outside court.

The Aug. 31, 2016 crash happened as Hernandez-Ruiz was driving her daughters, Delilah, 9, and Sayra Gonzalez, 7, from Petaluma to their school in Rohnert Park.

As she headed up Petaluma Boulevard North, she drifted into the median, overcorrected and plunged down an embankment. Her car flipped into the Petaluma River and quickly submerged in about 6 feet of water.

She got out but her daughters did not. Police and firefighters who dove into the water within minutes of the crash were unable to get them out in time.

Hernandez-Ruiz told CHP officers she had been cut off in traffic.

An investigation spanned more than a year before prosecutors charged her with crimes carrying up to 11 years in prison. She was arrested when she reported to court Sept. 22 and escorted by deputies Thursday to a San Francisco hospital for cancer treatment.

The judge may set a preliminary hearing date at her next scheduled court appearance on Oct. 27.

You can reach Staff Writer Paul Payne at 707-568-5312 or paul.payne@pressdemocrat.com.