It passed, 102-90.
Since then, Dean has taken the floor to speak on education, spending priorities, gun safety, and other issues, earning a reputation as a rising star in the Democratic caucus.
"She's given some memorable, forceful arguments," said House Democratic Leader Frank Dermody of Allegheny County. "That's maybe part of her legal training - she's a great debater. But also, she cares about [these issues], and it really shows."
She has also found ways to integrate socially with her colleagues, who sometimes call her by the nickname "Mad."
"This is a silly thing, but it works," she said, pointing to a photo of her smiling in a dugout with fellow legislators during a bipartisan softball game. "That simple act of getting out of the Capitol and throwing a ball around, making mistakes. We just had a lot of laughs."
Dean's predecessor, Montgomery County Commissioner Josh Shapiro, said he was impressed with how quickly she got up to speed.
"She moves the debate when she speaks," Shapiro said. "It's quite an accomplishment."
Dean, 54, is a lifelong resident of Abington, the youngest of seven children. She and her husband - Patrick Cunnane, chief executive of a bicycle distribution company - have three adult sons and a young granddaughter.
Dean spent three decades as an attorney in civil and contract law, and 11 years as a professor of writing, ethics, and rhetoric at La Salle University, her alma mater.
As a representative, Dean was paid $83,801 in 2013. She returned a $1,776 cost-of-living increase and did not take the per diem, car and phone allowances, according to expense reports.
Last year Dean proposed two resolutions that passed unanimously - one recognizing the 50th anniversary of Pennsylvania's ratification of the 24th Amendment ending the poll tax, and the other marking the 150th anniversary of the Gettysburg Address.
"I love Lincoln," Dean said. "As a teacher, every semester, whether it fit or not, I would teach the Gettysburg Address."
Four bills she sponsored died in committee in 2013. One would have required owners to report lost and stolen guns, and another would have reconvened a committee to study education funding.
With her experience as a lawyer and professor, Dean was an obvious choice for the Judiciary and Ethics Committees. But she also got some higher-profile assignments outside of her areas of expertise, including Appropriations and Finance, where she has delved into the governor's proposed budgets and spoken out for more education funding.
"Everything I'm looking at, constantly, is about education," she said. "I feel really lucky to be on Appropriations as a result of that. It's a place where I can constantly beat the drum that says it's the core function of what we do."
Although she is new to elected office, Dean said she has always "had the bug" for politics. She and her husband met through the Abington Rockledge Democratic Committee when they were in their 20s. Their oldest son works in the White House communications office.
"I always knew I wanted to get into public service," she said. When her youngest son was nearing the end of high school, "I thought, 'This is the time.' "
A local, part-time office wasn't her first choice, Dean said. But she was asked to run for the Abington Township Board of Commissioners and won the Ward 7 seat in November 2011.
Dean had been in office only a couple of months when she threw her hat into the ring to replace Shapiro in the 153d District, which represents Abington and part of Upper Dublin.
"It just occurred to me, of course I should take a shot," she said. "I really was hoping to join something and jump fully in."
She won the special election in April 2012 and was elected again in November of that year for a full term.
Dermody, the Democratic House leader, said he expected her to stick around awhile.
"I want to get really good at this," Dean agreed. "I've had good careers, but this one's the best."