Holt-Singh and three other women were taken hostage Wednesday by three armed suspects during a robbery of a Bank of the West branch in Stockton.
An hour-long chase with police ensued and two of the suspected robbers were shot and killed, along with Holt-Singh. The other two hostages and one of the suspects survived.
Dawn Holt described her sister as a "loving mother, sister, daughter and aunt, cousin."
"She was one of my best friends," she said.
Holt even offered her sympathies to the families of the two suspected robbers who died in the shootout.
"Even though my sister was the victim of a terrible crime, there are other people out there that have also lost someone," she said. "We do need to give that family, those families, respect because they've lost someone they love too."