Lexi Brown, Who Aided Other Kids with Cancer, Has Died at 12: 'She Passed Away Knowing How Very Loved She Was,' Says Father

Lexi Brown, 12, peacefully passed away with her mother beside her

Photo: Courtesy Jon and Lisa Brown

A California girl who raised thousands for pediatric cancer research while putting a brave spin on her own struggles with fibroblastic sarcoma – a cancer of the connective tissue – has died.

Lexi Brown, 12, who was recently interviewed by PEOPLE about her “Bald for Lexi” fundraisers and other events that have raised nearly $90,000 to help children with cancer, passed away Wednesday at a hospital in Toronto with her mother, Lisa Brown, at her side.

Lexi became ill on the way home from a pilgrimage to Lourdes, France, where she waded in waters renowned for their mysterious healing properties since 1858.

When their flight landed in Canada to refuel, Lexi was rushed to the hospital with breathing problems and died with her mom by her side.

“France was a trip that provided her miracle through spiritual healing, and she was at peace,” Lexi’s father, Jon Brown, 39, tells PEOPLE. “We would like people to know that Lexi passed away comfortably, on her own terms. She did not suffer at the end. She passed away knowing how very loved she was.”

Diagnosed in June 2014 with cancer after her mother found a lump on her leg following a school soccer game, Lexi, a seventh-grader from Santa Maria, endured numerous surgeries and chemotherapy treatments, all while helping to raise awareness for child cancer research.

“Everyone has done so much for me and my family that I thought it was important to do something to give back,” she told PEOPLE last month. “I feel better knowing that I’m doing something that can help other kids and their families.”

When it was discovered last fall that chemotherapy treatments had damaged her heart, Lexi continued her charity work, even after doctors told her family there was nothing more that could be done to help her.

“We don’t want to waste time being sad,” Jon told PEOPLE last month. “From the very beginning, Lexi has wanted to give back.”

“Whatever happens, we’re all so proud of her,” Lisa, 44, added in April. “She’s filled so many people with love, hope and strength.”

As news of Lexi’s passing spread through Santa Maria, community members responded by wearing Lexi’s favorite color – purple – and posting matching ribbons throughout the town.

Memorial services are pending, says her father, while the family makes arrangements to bring her body home from Canada.

“Lexi never gave up the fight and never lost the fight,” Jon says. “She fought until her tired body could not fight any more, and now we will continue to fight for her. We want everyone to know, Lexi knew how much you loved her.”