Ronke Phillips from ITV News London visited Fircroft Primary School in Tooting, where Imani Green was taught before she was killed during a family visit to Jamaica.
There she spoke to head teacher, Anne Wilson, who said: "She was a special little girl who was popular with staff and pupils alike."
She continued: "The school had given her special permission to travel to Jamaica because of her condition (Sickle Cell Anemia.) So the news was doubly tragic because she had gone there in an attempt to benefit her health."
This morning there was a special assembly at the school, where Reverand Andrew Davey from the local Holy Trinity Church, spoke to the children.
All the pupils from the school are being offered special counselling if they feel that they need it.
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The 52-year-old had previous convictions for violence but was not on the anti-terror watchlist.
In a statement Charlton Athletic said: Keith was a true hero who will be greatly missed by all the Charlton family and everyone at the club.
London and the worlds has united on Twitter in defiance of the West minster attack #prayforlondon #wearenotafraid