Kelly Cosby, who collaborated on a hip-hop song honoring U.S. Supreme Court Justice Ruth Bader Ginsburg before beginning her career at Duane Morris in September, died on Sunday after a battle with an aggressive melanoma. She was 25.

A Kansas City native, Cosby obtained her undergraduate degree at the University of Kansas and graduated from the New York University School of Law in May.

Shortly afterward, she was diagnosed with cancer, which in her final weeks ceased responding to treatment.

A few weeks ago, Cosby learned that she had passed the New York State Bar Examination, which she had taken several days after receiving radiation treatment, said Elaine Simeon, an associate with Duane Morris and a friend of Cosby's who also attended NYU Law.

Michael Grohman, the managing partner of Duane Morris' New York office and head of the firm's wealth planning practice group where Cosby worked, said the first-year associate had an "electric personality" and stayed positive even through her suffering, making those around her feel better.

"In many ways, she was a teacher and a mentor," Grohman said. "She really taught us how to live life, to balance adversity, to be brave and to be courageous."

Simeon, who said that she had convinced Cosby to come to Duane Morris, also described her as upbeat and selfless. When Cosby revealed her latest diagnosis, Simeon said, she was apologetic about breaking the news. "Even then, she thought of everyone else first and felt bad that she was going to make them sad."

As Cosby's condition deteriorated and Simeon began taking on some of her friend's pro bono work, she said Cosby still kept tabs on the assignments.

"There was never a sense of winding down," Simeon said. "She stayed positive and engaged."

New associates at Duane Morris, including Kelly Cosby, standing top right, perform the rap song Cosby helped write, "Notorious RBG," at an Oct. 15 firm meeting in Philadelphia.

Elizabeth Gavin, who co-wrote the tribute to Ginsburg, "Notorious RBG," with Cosby while they worked at the New York-based not-for-profit Global Justice Center in the summer of 2013, said Cosby "approached issues with a very compassionate heart."

"It sounds cliche, but she really is one of the sweetest, kindest, gentlest people that I have met," said Gavin, who is a law clerk for U.S. Magistrate Judge for the District of New Jersey Leda Dunn Wettre.

The song, which attracted 30,000 hits on YouTube, is a parody of The Notorious B.I.G.'s "Juicy" with lyrics about Ginsburg, such as: "You always fight/for equal justice/A diva in our eyes/Originalists can't touch this" and "I'm blowing up the glass ceiling for good/Call the chamber, same number same hood It's all good."

Gavin said Ginsburg has reputation as a "tough and simultaneously delicate" woman, words that she said could be used to describe Cosby. "Kelly was very, very fierce," she said.

Additionally, Gavin noted that Ginsburg was herself a cancer survivor—Cosby had won a previous bout with cancer when she was a 1L—which Gavin said was a "real point of connection" for Cosby.

NYU Law Dean Trevor Morrison, who clerked for Ginsburg from 2002-03, had a meeting with the justice in Washington, D.C. on Friday. Ginsburg penned a note to Cosby that Morrison was able to deliver to her on Saturday, which read: "To Kelly Cosby—Thinking of my favorite rapper with appreciation and affection, Cheers, RBG."

"Kelly was a shining example of grace, strength, bravery, and compassion—even in the face of tremendous adversity," Morrison said in a statement to the law school.

Matthew Ahn, a friend of Cosby's who also attended NYU Law and now clerks for Northern District Judge Lawrence Kahn, helped Cosby and Gavin produce the song.

He said that for Cosby, who worked with Amnesty International during her time at the University of Kansas, Ginsburg was the "culmination of several things that were special to her," including the fact that Ginsburg had been an attorney for the American Civil Liberties Union and, that during her time in law school and in the legal profession, Ginsburg found success in a "world where she was not necessarily welcome."

"It's just something that resonated with Kelly a lot," Ahn said.

A memorial service for Cosby was held at the NYU Law campus on Wednesday evening.

Reprinted with permission from New York Law Journal, © ALM Media Properties LLC. All rights reserved.