Tracy Bibby, 35, had been "showing off" before she lost control of the Ford Transit and it smashed through the front of Joan Woodier's home in Clevedon, north Somerset.
The van was left embedded in the front wall of the house, which collapsed on Mrs Woodier as she spoke to her son Alan Woodier on the phone at about 8.30pm on April 18 last year.
Bibby, of Rushmore, Clevedon, was convicted of causing death by dangerous driving and causing death while driving while disqualified following a trial at Bristol Crown Court.
Judge Michael Cullum jailed Bibby for four years and imposed an extended driving disqualification of six years.
The court heard Bibby had previously been banned from driving in 2006 and in 2016, when she was handed a three-year disqualification order.
"Because of your disqualification, you shouldn't have been driving that van at all," the judge told Bibby.
"You chose to do so wholly unnecessarily. You swerved the van from side to side. That appears to have destabilised the van.
"You were in some way showing off. The reality is what you did meant the van lost control. What then happened was tragic.
"The degree of the impact on the house was very significant. Mrs Woodier was effectively killed under the rubble.
"From her point of view, she would have been in no danger at all."
"I cannot get out of my mind the indescribable noise on the phone followed by deathly silence
Bibby had been at The Crab Apple pub moments before the incident, with CCTV there capturing her getting into the van on the driver's side.
She claimed she had then switched places with one of the passengers in the vehicle after driving away from the pub.
A police forensic collision investigation concluded that the van had driven into the house at between 32mph and 40mph.
The road's speed limit was 30mph.
Hannah Squire, prosecuting, said Bibby's speed was "inappropriate for the conditions".
"The inference is she was showing off, whether it was making the van 'dance' or driving like a racing driver," she said.
In a victim impact statement, Mrs Woodier's son Alan said the date of the incident "will never be forgotten".
"I cannot get out of my mind the indescribable noise on the phone followed by deathly silence," he told the court.
"After making a further three or four calls I sensed something was wrong so jumped into my car and arrived at Mum's to be greeted by the blue flashing lights of the emergency services.
"I knew instantly Mum had been killed, I knew where she would have been sat in relation to the impact and knew she was dead.
"I live with the regret that if I had not called her that day, at that time, then maybe she would still be with us."
His daughter, Jodie Cobb, described how Mrs Woodier was still cooking her own meals, coping with most household chores and pottering about in her garden aged 90.
She described her grandmother as a "kind and caring" person who had faced challenges with "determination, courage and strength".
"She coped and found the strength to overcome personal tragedies with that true British grit," Ms Cobb said.
Speaking after the verdict, Avon and Somerset Police collision investigation officer Tony Hall said: "Bibby has consistently refused to take responsibility for her reckless actions that night which tragically resulted in the death of Mrs Woodier.
"She sought to blame someone else, even though all the evidence pointed to her being the one behind the wheel."