The change of heart comes three months after she pleaded not guilty to the same crime in an arraignment.
On Oct. 19, Koval struck and killed Holman as he walked along state route 56. The 34-year-old Mira Mesa resident had gotten two flat tires and was trying to get help when he was killed.
Earlier that night he was celebrating his birthday with his sister and friends.
The 23-year-old Koval, a nursing student at Cal State San Marcos, didn't stop after striking Holman.
She turned herself in the next day and CHP investigators impounded her car which had considerable damage to the hood and windshield.
"Her whole windshield was destroyed, they said she had to stick her head out the side window to keep driving,"said the victim's father Kirk Holman.
The Holmans believe Koval was drunk and didn't turn herself in until she sobered up.
Prosecutors couldn't charge her with DUI because they couldn't prove she was intoxicated, although she was seen at two bars earlier that night. An empty beer can was also found inside her car.
The Holmans are glad they won't have to sit through a trial, but are worried Koval may get probation instead of prison time.
They're hoping she gets the maximum of four years when she is sentenced in June.
"She has really destroyed my family,"said the victim's mother Martha Holman.