The review at the site you linked made me want to watch it, too. 

I believe that the boy is probably about 11 or so, though. The girl who plays his sister is 14, but this is what it said about the boy:

<i>CAST JAMES E MARTIN - Telly

Born in 1992, James has previously appeared at the Bloomsbury theatre in the production of ‘A Christmas Carol’ in the role of Tiny Tim. KISS OF LIFE is his first feature film.</i>

Here's the synopsis for the movie that they gave, for those who have an aversion to following links to other sites:

<i>KISS OF LIFE (originally entitled HELEN
OF PECKHAM) marks the debut feature
of Emily Young, an exciting young British
talent. A Lodz Film School graduate,
Emily's previous short film, SECOND
HAND, won the Cinéfoundation prize at
the Cannes Film Festival in 1999.
KISS OF LIFE is a deeply moving journey
into the heart of a family.

Lithuanian actress Ingeborga Dapkunaite, best known for her role in 'Burnt by the Sun', stars as Helen, a London housewife barely coping with her two children and with her ageing father (David Warner) while her husband, John (Peter Mullan), an aid-worker in Bosnia is away from home.Taking the children to school one morning, she is killed in a car accident. Many miles away, in war-torn Eastern Europe, John is unaware that his wife has died. Helen herself, caught in limbo between life and death, watches over her family who struggle to come to terms with the loss of their mother and the continuing absence of their father. John has to travel home through dangerous terrain whilst Helen journeys through the space between life and death, freed only when she and her husband are able to reconcile their differences and experience the full meaning of their love for one another.

KISS OF LIFE is dedicated to the memory of Katrin Cartlidge, who was to have played the leading role of the mother but who died tragically just before filming began.</i>

Kind of spiritual-sounding, huh? 

It will be a spiritual experience for me to see how the 11-year-old boy handles such a sad situation in his life, for sure.

Love,
Sir J