Patricia Machin, 74, hugged Brian Williamson during the hearing in Bournemouth Crown Court, The Sun reported. The judge also read a letter Machin had written Williamson.
Judge Samuel Wiggs gave Williamson a suspended sentence for careless driving. Williamson said he was blinded by sun glare when he struck Gerrard Machin, 77, in December 2011 in Bournemouth.
"On the day of the accident, however bad it was for me, I realize it was a thousand times worse for you," Patricia Machin said in her letter. "Neither Gerrard, if he was here, nor I feel any sense of condemnation towards you."
Wiggs described Williamson as "very fortunate to have been forgiven." Scott Stemp, Williamson's lawyer, called the letter "truly astonishing."
Gerrard Machin died two months after he was hit by the car.
Toddler uninjured after being knocked over by Obama family dog
Martin Bashir resigns from MSNBC over Sarah Palin comments