Story highlights Brittany Maynard died Saturday, "in the arms of her loved ones," group says

"Love and peace to you all," she says in final message

Her story spread rapidly on social media

The 29-year-old said she had terminal brain cancer

Brittany Maynard, the 29-year-old who said she had terminal brain cancer, took medication to end her life under Oregon's "Death with Dignity Act," advocacy group Compassion & Choices said Sunday.

"Brittany chose to make a well thought out and informed choice to Die With Dignity in the face of such a terrible, painful, and incurable illness," a post on her website said . "She moved to Oregon to pass away in a little yellow house she picked out in the beautiful city of Portland."

In a statement, Compassion & Choices, an end-of-life choice advocacy group that has been working closely with Maynard, said she "died as she intended -- peacefully in her bedroom, in the arms of her loved ones."

Mourners grieve on social media

Maynard passed away Saturday, said the group, which released an official obituary.

Photos: Brittany Maynard's journey Photos: Brittany Maynard's journey Brittany Maynard's journey – Brittany Maynard with her dog Charley in San Francisco. Maynard, a 29-year-old with terminal brain cancer, has died, advocacy group Compassion and Choices said in a Facebook post on Sunday. Click through to see more photos of Maynard's life. Hide Caption 1 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard, second from right, visits the Grand Canyon with her family in October. She had said the Grand Canyon was the last item on her bucket list. Hide Caption 2 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard at age 4 with her mom, Debbie. Hide Caption 3 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard with her mom during a trip. Hide Caption 4 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard, right, poses for a photo during her travels. Hide Caption 5 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard and her husband, Dan Diaz, on their wedding day. They had been married a little more than a year when she was diagnosed with brain cancer. Hide Caption 6 of 7 Photos: Brittany Maynard's journey Brittany Maynard's journey – Maynard shares a moment with her bridesmaids on her wedding day. Hide Caption 7 of 7

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The epitaph contained a final message from Maynard, who expressed a note of deep thanks to all of her supporters, whom she "sought out like water" during her life and illness.

"It is people who pause to appreciate life and give thanks who are happiest. If we change our thoughts, we change our world! Love and peace to you all," she said.

Maynard graduated from University of California, Berkeley, and earned a Masters in Education from University of California, Irvine, according to the obituary. She was a world traveler who volunteered at a local animal rescue organization before her diagnosis and lived 29 years of "generosity, compassion, education, travel, and humor," it said.

Maynard is survived by her husband and his family, her mother and stepfather.

"While she had longed for children of her own, she left this world with zero regrets on time spent, places been, or people she loved in her 29 years," the obituary said.

Maynard's story spread rapidly on social media as a video explaining her choice garnered more than 9 million views on YouTube.

She became a prominent spokeswoman for the "death with dignity" movement, which advocates that terminally ill patients be allowed to receive medication that will let them die on their own terms. She also became a lightning rod for criticism from people who oppose that approach

"I quickly decided that death with dignity was the best option for me and my family," Maynard wrote in an opinion column for CNN explaining her choice. "We had to uproot from California to Oregon, because Oregon is one of only five states where death with dignity is authorized."

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"I still feel good enough, and I still have enough joy, and I still laugh and smile with my family and friends enough that it doesn't seem like the right time right now. But it will come, because I feel myself getting sicker. It's happening each week," Maynard said in the video, which was produced by Compassion & Choices and released to CNN last Wednesday.

Maynard said she had stage IV glioblastoma multiforme, an aggressive form of terminal brain cancer.

When she first started speaking out about her decision, Maynard said that in early November she planned to take the medication she'd been prescribed. In her latest video, she said she was waiting to see how her symptoms progress before deciding on a date.

But taking too long to make that choice was one of her greatest fears, Maynard said.

"The worst thing that could happen to me is that I wait too long because I'm trying to seize each day," she says, "but I somehow have my autonomy taken away from me by my disease, because of the nature of my cancer."