This picture comes from the Catholic Tradition site (http://www.catholictradition.org/Mary/olhc.htm), which gives a nice history of the statue, which now stands in St Mary's Cathedral, Sydney.
The title of Our Lady as help of Christians comes primarily from her intervention in the Battle of Lepanto against the Turkish Muslims, though the feast was in fact instituted for the papal states in 1816 by Pius VII after being freed from imprisonment by Napoleon through her intercession.
Our Lady, Help of Christians was adopted as patron of Australia in 1844, and was confirmed by the Holy See in 1852.
Australia at this time perhaps needs above all more workers for the vineyard, so perhaps this prayer of St John Bosco is the one we should adopt for the day:
Most Holy Virgin Mary, Help of Christian,
how sweet it is to come to your feet imploring your perpetual help.
If earthly mothers cease not to remember their children, how can you, the most loving of all mothers forget me?
Grant then to me, I implore you, your perpetual help in all my necessities, in every sorrow, and especially in all my temptations.
I ask for your unceasing help for all who are now suffering.
Help the weak, cure the sick, convert sinners.
Grant through your intercessions many vocations to the religious life.
Obtain for us, O Mary, Help of Christians, that having invoked you on earth we may love and eternally thank you in heaven.