Giffords, who was hosting a meet and greet for constituents when she was attacked, will light a candle for the victims during a public vigil at the University of Arizona.
She battled from the brink of death to relearn how to walk and regain a limited ability to speak after being the first person hit, at close range with a shot to the head, when the gunman invaded the event at a supermarket car park in Tucson.
Suspect Jared Loughner, is alleged to have shot a further 18 people before he was overpowered by bystanders.
News of the massacre shocked the country, not least because it occurred at what was intended to be a casual and friendly opportunity for the public to meet their representative in Congress and also because one of the victims, Christina-Taylor Green, was a nine-year-old child.
But shock turned to outrage when it emerged Loughner, 23, who was later indicted by a grand jury on 49 counts of murder and attempted murder, might never face justice.
Diagnosed by doctors as schizophrenic and psychotic and ruled unfit to stand trial, Loughner and his lawyers are embroiled in a battle over the legality of prison officials forcing a defendant to take medication in order to make him fit for court.
Three judges on a federal appeals court panel ruled last summer that Loughner enjoyed more rights than a convicted inmate and could not be forcibly medicated.
But authorities at the US Medical Centre for Federal Prisoners in Missouri, where Loughner is being held, continue to treat him, arguing that the judges’ ruling allows them to take any necessary steps to protect the prison staff, other inmates and Loughner himself.
Tomorrow’s vigil will therefore take place against the backdrop of an ongoing hearing in the 9th Circuit Appeals Court that will determine Loughner’s fate.
The ceremony’s participants, however, say they prefer to concentrate on remembering the dead and injured.
“I don’t think about him. As long as he never hurts anyone ever again and is never able to get out, I’d be OK with that,” said Roxanna Green, Christina-Taylor’s mother, when asked about Loughner during an interview.
Meanwhile Giffords, who lost 50 per cent of her vision when she was shot in the head, and who is still undergoing intensive rehabilitation therapy in Houston, Texas, will attend the vigil with her husband, retired Nasa astronaut and space shuttle commander Mark Kelly.
An experienced public speaker, Kelly will deliver an address on his wife’s behalf to honour the victims, who included her aide Gabe Zimmerman and Arizona’s chief judge John Roll.
“Congresswoman Giffords wanted to be back in Tucson for this very emotional weekend. She felt it was important to be in her hometown with her family, staff members and a few close friends,” said Pia Carusone, Giffords’ chief of staff.
The vigil will also see a moving reunion between Giffords and Christina-Taylor Green’s family, who last met in November when Kelly presented the dead girl’s brother Dallas with a model space rocket.