12-Year-Old California Girl with Grim Cancer Diagnosis Faces Life with a Smile, Raising Thousands to Give Other Sick Children Hope

"We don't want to waste time being sad," her father tells PEOPLE

Photo: Courtesy Jon and Lisa Brown

It’s the kind of news that nobody wants to get, especially a 12-year-old girl who loves playing soccer, riding roller coasters, gossiping with friends and dancing to Top 40 hits.

Nobody expected the unusual bump on Lexi Brown’s left leg would lead to a grim cancer diagnosis with no further options, but that is what happened about two years ago. Even more stunning was the Santa Maria, California, seventh-grader’s response.

While she was battling fibroblastic sarcoma, a cancer of the connective tissue, Lexi decided, why not help other children facing similar challenges by raising funds for cancer research?

So barbecues and bake sales were scheduled, along with an annual “Bald for Lexi” fundraiser, with supporters promising to shave their heads in exchange for donations. At the first event in 2015, $18,000 was raised. Then last month, 94 people shaved their heads, raising nearly $73,000.

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

It was June 2013, when Lexi’s mother, Lisa Brown, 44, an administrative assistant, found the lump on Lexi’s thigh while giving her a massage after a grueling soccer tournament. Because Lexi had no symptoms that anything was wrong, her doctor said it was nothing to worry about. One year later, though, when the lump was still there, Lisa took her daughter in for an ultrasound, an MRI and a biopsy.

Lexi’s cancer diagnosis was shocking enough. But then, while removing the tumor, surgeons discovered that it was much larger than they expected. Lexi went through several rounds of chemotherapy and radiation, but the cancer kept coming back. Last year, in June, doctors found spots on her lungs. Then, shortly after that, when Lexi ended up in the emergency room with shortness of breath, it was discovered that chemotherapy had damaged her heart.

Last month, when a recent scan revealed that her tumors were still growing, Lexi was taken off treatment.

“There is just not much more that anyone can offer,” her father, Jon Brown, 39, who works for the California Department of Transportation, tells PEOPLE. “We don’t know how much time we have left together, so we don’t want to waste time being sad. From the very beginning, Lexi has wanted to give back. We’re focusing on that, plus spending all the time we can knocking off items on Lexi’s bucket list.”

Although those items have included visiting the Statue of Liberty, attending a Los Angeles Dodgers baseball game and going to Disneyland as often as possible, Lexi’s biggest wish is to raise funds for cancer research and to help other children who are in a fight for their lives.

“There have been so many setbacks, but she’s inspired thousands with her positive attitude,” says Lisa, who has one other child, Carter, 14. “Yes, it’s been hard. We could all go to our rooms, cover our heads and give up. But how is that going to help anybody?”

People from around the world have donated to Lexi’s cause and to her GoFundMe account, which her family hopes will eventually become a college fund.

“We’re praying for a miracle,” says Lisa. “Lexi dreams of becoming a physicist. Whatever happens, though, we’re all so proud of her. She’s filled so many people with love, hope and strength.”