Rainham Road South was closed on Sunday (March 9) at 9.20pm between Dagenham East station and the Shell Petrol station.
Emergency services were called to the scene and medics treated three people.
The woman was taken to hospital, while two children were discharged at the scene.
The Metropolitan Police says it is unable to provide further details about the crash or the woman’s condition.
A London Ambulance Service spokesperson said: “We were called at 9.20pm on Sunday 9 March to reports of a road traffic collision on Rainham Road South, Dagenham.
“We sent an ambulance crew and a clinical manager to the scene.
“We treated three people. We took a woman to hospital and discharged two children at the scene.”
