On the last day of Brittany Maynard's life, she woke to a seizure.
"We got up rather early and she was feeling a little weird," her husband Dan Diaz tells PEOPLE.
"After a seizure she'd be unable to speak for a while and when she did, it was just gibberish," he says. "So when we got up there was a little bit of that. I said, 'Let's just sleep in.' "
Maynard, 29, was terminally ill with brain cancer. She ended her life on Nov. 1 with medication prescribed to her by her doctor, something that is legal for certain terminal patients in Oregon.
Maynard and her family had moved to the state last June so she could get access to Oregon's Death with Dignity Act.
Before her death, Maynard launched an online video campaign with Compassion & Choices to push for laws similar to Oregon's to be passed nationwide.
Diaz, who promised his wife he'd continue to lobby for the laws after her death, opened up to PEOPLE about her last hours.
After Maynard's seizure around 7 a.m., the couple went back to sleep, then got up about 9 or 9:30 a.m. and ate breakfast.
"She wanted to go and take a hike so we all went and hiked," Diaz, 43, says. "There were eight of us total and the dogs. We went on a trail that she liked and it was a good morning. Then we got back to the house."
Later that afternoon, Maynard "just knew it was time," her husband tells PEOPLE, adding that the seizure that morning "was a reminder of how sick she really was." Even as she prepared to take a fatal dose of secobarbital, Maynard was laughing and joking with Diaz and her family.
"She was surrounded by the people who loved her and her passing was peaceful," he says, adding that further details are "sacred."
Diaz supported his wife's decision all the way. "Brittany's symptoms were bad and they were getting worse," he explains. "She did what was right for her and avoided needless suffering and a tortuous death."
For more from Maynard's family, pick up the latest issue of PEOPLE, on newsstands Friday