Ethan Sarkar, 14, and his father Derek, 46, from Birmingham, died when their Volkswagen Golf collided head-on with a Volvo on the A614 near East Cowick on Saturday.
The driver of the Volvo, Sheila Stavert-Lee, 70, from Wigginton, near York, was also killed.
Mr Sarkar’s wife, Karen, 43, and daughter, Abbie, were airlifted to Leeds General Infirmary after the crash, which happened on a bridge over a canal.
The hospital described Mrs Sarkar’s condition as “poorly” and said Abbie was “stable”.
Police said it appeared that Mrs Stavert-Lee’s car crossed on to the wrong side of the carriageway, into the path of the oncoming Golf.
The pensioner’s daughter told rescuers that her mother had been on the way to see her husband in Doncaster Prison.
After the crash, Ethan’s best friend described him as a popular and hard-working boy who was “always smiling”.
Connor Meredith, also 14, said he had been devastated by news of Ethan’s death.
He said he believed the family had been visiting relatives for a birthday celebration