The charges came Wednesday, nearly six months after Gavyn Barnett was killed in the collision.
The toddler's mother, Angela Barnett, was crossing 5600 West and 4005 South in West Valley City on June 10 about 9:15 p.m. with her 9-year-old daughter by her side and her son in a stroller.
The area was poorly lit, police said. There was no crosswalk.
As the mother moved toward the sidewalk with her children, a car crashed into the stroller.
The impact sent the stroller and the child inside it flying.
Gavyn Barnett landed in the road. He was taken to Primary Children's Hospital, officials said, but later died from his injuries.
In interviews with police, the mother said she saw the car that hit her baby stop briefly before continuing on.
After months of investigating, police received a tip from family members of Muñoz's ex-boyfriend, who told police that she was responsible for the crash.
Muñoz told detectives that she had forgotten her glasses that night. It was dark and she "couldn't see very well," according to charging documents. She didn't see anyone crossing the road.
After she realized she had hit someone, she "stopped her car, looked into her rearview mirror and saw a stroller," the documents state, "but got scared and drove off."
She never called the police.
Muñoz was booked into jail last week She remains there in lieu of $50,000 bail.