The family were travelling to Butlins in Skegness where Carley Ann and Bethany were due to take part in adance competition when their car collided with a lorry on the A18.
The young people will also visit key venues in Maritime Greenwich, enjoy a special boat trip and treasure hunt using a specially devised mobile phone app, take part in a large-scale dance extravaganza, Making Waves, and enjoy a conference opening event in the spectacular Painted Hall at the Old Royal Naval College, a location for many celebrated movies including Pirates of the Caribbean: on Stranger Tides.