She's the real-life waitress who became a lawyer to free her brother from prison for a murder he didn't commit.
The two women greeted each other on the red carpet at the movie's New York premiere Tuesday.
"Betty Anne is my real life hero," said Swank.
In 2001, Betty Anne represented her brother Kenny. He was exonerated for the1980 brutal murder of a Massachusetts woman.
It was the culmination of a dramatic 18 year journey for Betty Anne.
She'd been a waitress at a Rhode Island pub and a single mom with two kids with only a high school equivalency when her brother begged her to save him by going back to school.
"He said, 'I don't care how long it takes. Promise me you'll go back to school and become my lawyer,' " recounted Betty Anne.
In Conviction, actor Sam Rockwell plays her brother.
She went back to school, graduating from college, then law school, and doggedly searched for the DNA evidence that cleared her brother of any role in the murder.
"It's horrifying knowing your brother is in jail for something he didn't do," said Betty Anne.
Betty Anne's grit and determination has been compared to another real-life heroine, Erin Brockovich, played by Julia Roberts.
But here's what you won't see in the movie about Betty Anne's incredible life.
Just six months after he got out of prison, her brother hit his head in a fall and died. It was a tragic ending to what should have been a fairy tale story.
Betty Anne never worked as a lawyer again, nor had another client. All she wanted to do was clear her brother's name and go back to the restaurant where she is today, not waiting tables, but working as the manager.
Swank said, "She just reminds you what's important in life: family and the people you love."