"It's very difficult, but when they told me I was going to be OK, the only thing I could do was give it to God and hold on tight and don't lose my faith," said Roberts, who is from Oswasso, Okla.
Williams lost his mother, Deborah, to breast cancer in 2001 and pitches with a pink glove every game in her honor.
"Every year since I was in Taiwan [in 2010], after I get my first win I give my glove away," he said. "I thought it was a good gesture for her to have the glove of my first win with the Astros, and that's what I did. I gave her my game-used glove and signed it."
During summer 2012, Roberts learned she had stage four breast and lymph node cancer. The original prognosis from her doctors was not encouraging, and Roberts took on her treatments with great strength and courage.
The cancer spread to her neck last spring, and she underwent painful radiation treatments without the use of pain medication because of an allergy. The radiation treatments continued throughout 2013.
"I'm in complete remission now," said Roberts, who received a clean bill of health Feb. 1.
While she was recovering, Roberts stayed busy by traveling to watch the baseball games of her teenage son, Colton, who plays on a competitive team.
"Baseball's a big part of our life and getting through this," she said. "My son played games, and that got me through the treatments, along with my brother and family. It does mean a lot to be able to be here and know that I defeated cancer."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.