The three-year-old boy, visiting Jersey from the UK, was hit by a car near the Millennium Town Park just before 4 pm yesterday afternoon.
Police say the woman has since been released on bail.
Meanwhile, another visitor from the UK, a 73-year-old man, is still in hospital after the car he was driving crashed into railings at the Harbour yesterday afternoon.
The entrance to the Elizabeth Terminal was closed off for a period after the crash, which happened just after 1 pm. No other cars were involved and the entrance to the Terminal later partially opened to let vehicles and passengers through to board a ferry.
The man was treated at the scene by paramedics before they took him to A&E. The Health Department say he is currently in a stable condition.
