The mother of the woman who was killed while protesting a white supremacist rally in Charlottesville has urged mourners at a memorial service to "make my child's death worthwhile".

Heather Heyer, the 32-year-old paralegal, was killed on Saturday after a car rammed into a crowd of anti-racist and anti-fascist demonstrators.

James Fields, the 20-year-old driver of the car, has been charged with murder.

"They tried to kill my child to shut her up. Well, guess what? You just magnified her," said Heyer's mother Susan Bro as she received a standing ovation from the hundreds who packed a downtown theatre on Wednesday.

READ MORE: Charlottesville attack - What, where and who?

"She paid attention. And she made a lot of us pay attention.

"I want this to spread. I don't want this to die. This is just the beginning of Heather's legacy."

Heyer's death - and President Donald Trump's insistence that "both sides" bear responsibility for the violence - continued to reverberate across the country, triggering fury among many Americans and soul-searching about the state of race relations in the United States.

The uproar has accelerated efforts in many cities to remove symbols of the Confederacy.

Heyer's father, Mark Heyer, wearing a violet polo shirt and voice breaking with emotion, told the gathering how truly proud he was of his daughter.

"I came here today, and I was overwhelmed by the rainbow of colour in this room," he said. "That's how Heather was."

In the crowd were Virginia governor Terry McAuliffe, US Senator Tim Kane and Charlottesville mayor Mike Signer.

Later on Wednesday, hundreds held lit candles and sang songs of love and fellowship in Charlottesville to remember Heyer at what was billed as a vigil for unity.

I can only imagine what she's going through as a mother, but I do know that this is a truly inspiring human being #HeatherHeyer https://t.co/rERbSnLjNr

— Nithin Britto (@NithinBritto) August 17, 2017

"The violence that was brought at the tip of the spear by those carrying the Swastikas for rallies like we saw, that's one expression of it, but it is empowered by so many systems in the United States," Seth Wispelywey, a grassroots organiser, told Al Jazeera.

Amid concerns that trouble could erupt outside Wednesday's memorial, a small group of anti-racist protesters, wearing pink helmets and carrying baseball bats and purple shields, stood quietly near the theatre.

One of the group, who declined to be identified, said they brought weapons to defend themselves in case the white supremacists returned.

"The cops didn't protect us on Saturday, and we don't trust them to do so today," the group member said.

READ MORE: Charlottesville - Witnessing the 'monstrous' attack

Outside the theatre, near where Heyer was killed, artist Sam Welty was chalking a large portrait of her on a memorial wall that features many tributes to her.

"The way she lost her life, doing what she did, really stood for Charlottesville," said Welty.

On Monday, Trump bowed to political pressure and denounced neo-Nazis and the Ku Klux Klan by name.

A day later, however, he inflamed tensions by insisting counter-protesters were also to blame.

White nationalists called Saturday's rally to protest against plans to remove a statue of General Robert E Lee, commander of the pro-slavery Confederate army in the US Civil War.

Undeterred by the clashes, state and city leaders in several southern US states have vowed to step up efforts to remove such monuments from public spaces.

Baltimore dismantled four Confederacy-related monuments under cover of darkness, including statues of Lee and General Thomas "Stonewall" Jackson.

The mayor of Birmingham, Alabama, had the city's 52-foot Confederate memorial obelisk covered over with wooden panels.