Brooke Williams, the niece of George Floyd, spoke at her uncle’s funeral in Houston, Texas.
She remembered Mr Floyd as spiritually grounded and an activist and said that ‘justice would be served’ for him as long as she is breathing.
Ms Williams added that the laws were designed to disadvantage black people.
Mr Floyd died in Minneapolis in May as a white police officer held a knee on his neck for nearly nine minutes.
Derek Chauvin has made his first court appearance, where he faces charges of second-degree murder and manslaughter.
Three other arresting officers are charged with aiding and abetting murder.
They have all since been fired.