SAN JOSE -- A Gilroy woman has been convicted of killing her own husband and grown daughter by crashing her truck with them as passengers while she was high on a potent mix of alcohol and prescription pain medicine.

Stacy Lonnberg, 47, was driving her family on Highway 85 in San Jose to a wedding in Belmont in January of 2012 at speeds of more than 80 mph when her Toyota pickup truck side-swiped another truck, veered across the lanes and flipped over six times. Her 1-year-old grandson, who was strapped into a booster seat in the back, survived the crash.

But her husband, UPS truck driver Fred Lonnberg, 57, and daughter Tiffiny Gillette, a 26-year-old hair stylist who was not wearing a seat belt, both died.

Lonnberg faces up to 36 years to life after being convicted Tuesday of two counts of second-degree murder and one count of child endangerment. Judge Ron Del Pozzo is set to sentence her Oct. 11.

During the trial, prosecutor Matt Braker revealed that Lonnberg had driven drunk "hundreds of times in disregard of a warning from the court in 2005, and the safety of everyone else on the road."

The CHP officer who handled the accident said she was so drunk after the crash just north of the Winchester Boulevard exit that she seemed unconcerned about her husband or daughter. Her blood-alcohol level was at least 0.20, more than double the legal limit, and she also tested positive for Oxycodone, a powerful painkiller.

"We have to get more information back (from the probation and sentencing report) before we decide what sentence we'll seek,'' Braker said, "but I certainly don't think the minimum punishment under the law, 15 years to life, is sufficient.''

Contact Tracey Kaplan at 408-278-3482. Twitter.com/tkaplanreport.