On Saturday, they hosted a charity event to mark what would have been her 25th birthday, and celebrated her life by doing something she loved - dancing.
"Today's a day that, you know, that's indelible in our memories, an event that occurred three months ago," said Brianna's father, Todd Kupfer. "We wanted to have a day where we really honored her and appreciate all the great values that she stood for."
In January, Brianna was working alone at the Croft House furniture store in the 300 block of North La Brea Avenue, when a man walked in and attacked her. She died at the scene.
Authorities arrested a 31-year-old transient, Shawn Leval Smith, and charged him with her murder.
RELATED | Suspect in stabbing death of Brianna Kupfer charged with murder, LA County DA announces
Dozens of people took part Saturday in a memorial run/walk at Brianna's alma mater, Brentwood School.
Friends say Brianna was a caring and fun-loving person who enjoyed yoga and spending time outdoors.
"All these activities are things that she loved because she was very fun-loving, carefree, like considerate, just all the great things," said Lauren Klotz. "It really brought a lot of people together."
"She just had a magnetic, positive spirit about her that kinda was undeniable, and all these people just loved her so much and are here to support her," Kendall Klotz added.
The event served to kick off a foundation honoring Brianna.
Kupfer says his daughter had a huge heart and had set many goals for herself.
"She was a person that just lived, in my view, like a pure life,' he said. "She was really good with people, and good with everybody, and was really caring."
The foundation will focus on the environment, women's advocacy, and other social issues that meant a lot to Brianna.