(CNN) A few years ago, Sarah Hughes could barely walk. She weighed 83 pounds and was crippled by constant pain due to a rare type of juvenile arthritis.
Now, Hughes, a 25-year-old resident of Fulshear, Texas, feels stronger and happier. She is even planning nuptials as a new fiancée, and she attended President Donald Trump's congressional speech Tuesday night, which was Rare Disease Day.
She credits an experimental stem cell treatment with giving her new hope for her health and her future -- a newfound hope that also caught attention of Republican Rep. Pete Olson.
Olson, who represents Texas' 22nd district, invited Hughes as his guest of honor at Trump's first address to a joint session of Congress.
Olson said he read news reports about Hughes and her health battle around the time Congress was working to pass the 21st Century Cures Act, a medical research bill, last year. Olson was so moved by Hughes' story that he even shared it on the House floor, he said.
"She is the face of the 21st Century Cures Act because of what she's gone through in her life," he said Tuesday.
"It became pretty clear to me that ... I (have) got to tell her story," he said. "That's why she's here: She's awesome."
In a rare bipartisan vote November 30, the House of Representatives approved the 21st Century Cures Act, intended to boost funding for medical research on cancer and other diseases, such as Hughes'. It went on to be approved by the Senate and was signed into law by President Barack Obama.
Immediately after the House vote, Hughes said, Olson called her at home to invite her to be his guest of honor.
"I was at home baking cookies with my mom after watching Representative Olson tell my story on the House floor with a huge poster with my picture on it. I was overwhelmed and excited by this huge honor and attention given to me and my story," said Hughes, whose story appeared on CNN in 2015.
"I still cannot believe I will be in the same room as our President and lawmakers," she said before attending Trump's speech.
Trump also invited a guest with a rare disease to the joint address, Megan Crowley, a 20-year-old sophomore at the University of Notre Dame who was diagnosed with Pompe disease when she was 15 months old. At diagnosis, she was not expected to live for more than a few years, according to a White House statement.
It took Crowley's father, John, to launch the New Jersey biotechnology company Amicus Therapeutics to identify a drug treatment that would save her life, Trump said.
"But our slow and burdensome approval process at the Food and Drug Administration keeps too many advances, like the one that saved Megan's life, from reaching those in need," Trump said in his speech.
"If we slash the restraints, not just at the FDA but across our Government, then we will be blessed with far more miracles like Megan," he said. "In fact, our children will grow up in a Nation of miracles."
At 11 months old, Hughes was diagnosed with systemic juvenile idiopathic arthritis, a debilitating autoimmune illness that affects multiple organs and systems. It can cause joint swelling, pain, fevers and rash.
Hughes spent most of her adolescence hospitalized, as she became so sick that she could barely walk and suffered immense pain. Her body was evaluated, treated and studied at the National Institutes of Health in collaboration with her doctors from the University of Texas Health Science Center at Houston.
Yet relief came in 2014, when Hughes received a high-dose adult stem cell treatment that was not approved in the United States.
For the procedure, Hughes had her own healthy stem cells cultured at the FDA-registered biotechnology company Celltex Therapeutics in Houston. Then she traveled to Cancun, Mexico, to have the cells infused back into her body.
Each infusion involved about 200 million stem cells, and Hughes received some 22 infusions over almost two years. The cells could help normalize her immune system, which was overactive due to her autoimmune disease.
Before the stem cell therapy, Hughes said, she was taking 23 medications a day. Now, she is on eight medications at lower doses.
Hughes shared her experience in a speech before Food and Drug Administration officials during a hearing on stem cell clinics in September.
"If not for the help of high-dose autologous mesenchymal stem cell therapy, I would not be here today," Hughes said at the hearing.
"I was running out of time, but I was willing to put my life at risk to get on an airplane. My quality of life had become so dismal, even one small improvement from my own stem cells would have been enough for me," she said in her speech. "What happened in the days, weeks and years following my first infusion has changed my outlook. It's hard to believe, in my sick body, I had a wealth of healthy adult stem cells with the ability to so significantly improve my quality of life."
Hughes looks forward to representing the 117 million Americans who have one or more chronic health conditions at Trump's congressional address.
"My hope is that our new President will spend time looking at how to help all Americans have access to new therapies like the one I had," she said.