The child, then aged seven, was holding a candle when their home-made sheep costume caught fire.
The child suffered 45 per cent burns leading to life-changing injuries which left them dependent on care for basic needs.
In June St Thomas Beckett Catholic Primary school was found guilty of health and safety breachers in a case at Southwark Crown Court.
The incident happened in December 2019 outside Our Lady of the Annunciation Church in Bingham Road, Croydon.