Two more leads found to narrow down the search.
Second child of John and Honora Keady, Patrick was Baptised in RC Parish of Laurencetown on 8 April, 1837. Near the County boundary for Roscommon. Record found with local historical society, but no trace of other family members.
Record found for Maria Keady, who had a twin brother John Francis Keady, born 1840 about a year and a half before the family arrived in Melbourne. Record for Maria shows, Born 28 January 1840, Drum, Roscommon. RC Parish of St Peter's, Athlone and Drum. Parents names given as Joannis Keady and Maria Kenny, presumably Latin for John and Mary. Mary being Honora's second name.
Sadly, Mary died in Melbourne sometime in 1842.
These leads may help others in their search.