Investigators now believe a Windsor woman killed on Highway 101 early Sunday when her car struck a tree may have suffered a medical emergency prior to the crash.

Sheryl "Sherri" Greenlee, 53, had been driving on the Fulton Road exit ramp when she lost control of her Ford Mustang and struck a redwood tree. She was not wearing a seatbelt.

"Based on the extent of her injuries, it didn't appear that the crash was the cause of death," CHP Officer Jon Sloat said. An autopsy was conducted Monday and additional tests have been ordered, he said.

Family and community members recalled Greenlee as a generous mother of three who volunteered untold hours supporting Windsor High School athletic programs.

"Whenever I needed some help — any time — if she wasn't working, she was there," said Dave Kahn, president of the Windsor High School boosters. "Sherri was a lovely person. I never heard anything negative from her about anything."

Greenlee, whose younger son, Eric, wrestled and played football for the Jaguars before graduating last spring, was a staple in the snack bar, serving up nachos and supporting the school.

"She ran the counter, taking care of the kids," Kahn said. "She was always friendly."

Greenlee, a floral manager at Safeway in Sebastopol, became a first-time grandmother eight months ago when her daughter, Robin Deck of Windsor, gave birth to Cameron.

"I think honestly she was the best grandmother for him I could have imagined," Deck said.

Deck spoke with her mother Saturday night, saying she no longer needed to show up to care for Cameron, but her mom came anyway, Deck said.

"She came over anyway to spend time with him," Deck said. "It was right after she got off work and she was so tired but she came over anyway."

In addition to Deck, Greenlee is survived by sons Eric Greenlee of San Diego and Ben Greenlee of Windsor.

A memorial service is scheduled for noon Saturday at Shiloh District Cemetery, 7130 Windsor Rd.. Donations may be given to the Sherri Greenlee Memorial Fund at Exchange Bank, 8700 Lakewood Dr., Windsor, 95492