This is above the legal limit of 0.08 in the state, CBS SFBay Area reported.
The toxicology results also showed Sarah Hart and two of the children had a "significant amount" of an ingredient primarily used in Benadryal, a medication used to help people sleep, in their systems. The office was still waiting on toxicology results from a third child.
CrimeOnline will provide additional updates when more information is available.
The body was found at the Dimmick Overcrossing on the Eel River where the family's SUV was swept away and submerged.
Investigators believe the family's other three children, 15-year-old Sierra Hart, 16-year-old Hannah Hart and 15-year-old Devonte Hart were in the SUV at the time of the crash but their bodies have not been recovered.
No one in the vehicle, a GMC Yukon, was wearing a seatbelt, Captain Carpenter said on Friday.
Mothers Sarah and Jen, both 38, died, as well as their children Markis, 19, Abigail, 14, and Jeremiah, 14.
"It appears she (Hart) was about 70 feet from the edge and accelerated from there", Carpenter said. "Several items have been positively identified, by family members, as belonging to the Thottapilly family". Child services officials attempted to visit the Harts on March 23, after neighbors reported that one of the children, Devonte, had come to their house multiple times asking for food.
KGW obtained a 911 call that provided further clues to what was happening when the Harts left their Washington home and drove to California.
Last August, soon after the Harts moved into their rural home, neighbors Bruce and Dana DeKalb said a child rang their doorbell, seeking sanctuary from abuse.
The juvenile has not yet been identified but authorities believe the child had been in the SUV.
In 2010, Sarah Hart pleaded guilty to misdemeanor domestic assault involving one of the children, according to Douglas County, Minnesota, court records.
It is still unclear why the vehicle was driven into the ocean with the family from Washington in late March.
Beginning in 2008, Sarah and Jennifer Hart faced repeated child abuse allegations from teachers and neighbors as they moved from Minnesota to OR to Washington with their six adopted children.
A family of four taking a West Coast road trip vanished about 30 miles from the site of the Hart family crash, authorities said this week.
The 15-year-old made headlines in 2014 after a photographer shot a photo of him hugging a police officer during a protest after the decision was made to not press charges against the officers who shot and killed Michael Brown in Ferguson, Missouri.