The girl's parents and brother were taken to hospital and their injuries were not thought to be serious.
The male driver of the Peugeot was arrested and taken into custody. A female passenger was taken to hospital suffering from minor injuries.
The incident happened just before 6.30pm and police, ambulance and fire crews attended.
The Metropolitan Police said the pursuing police car had its blue lights and sirens on when the collision happened.
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Police said the child, who was without a driving licence, was trying to make his way 2,500 miles from the east coast to Perth.
The 24-year-old was charged with 14 counts of wounding with intent to do grievous bodily harm and one count of throwing a corrosive fluid.
Winds will veer northerly overnight with colder air streaming in over the next few days.