Met Police say Olivia is described as:
- Light skinned black female, 5ft 5 inches tall
- She has long, blond and brown plaited hair
- She was last seen wearing a dark green hooded coat, a white school polo shirt, black trousers and black shoes
- She has a mental age of five-years-old
Anyone who has seen her or who knows of her whereabouts should call police in Enfield Borough on 07825832887 or 101.
More top news
Hundreds of people do no know when they will be allowed back home after a 'serious incident' was declared in east London.
A Tube and rail strike planned for Wednesday evening could bring the capital to a standstill causing travel chaos for millions of commuters
The only Muslim survivor of the 7/7 terror attack in London has urged the country to stand together against Islamophobia.