Considine family from SixMileBridge

Hi,

I have a 3g-grandmother - Margaret Considine - who emigrated to Australia with her sister Bridget, both apparently from SixMileBridge, arriving in Australia in Oct 1836. The immigration records give their ages as Margaret 21 (so born ~1815) and Bridget 20 (so born ~1816), but their death records suggest dates of birth slightly later - Margaret died aged 77 in July 1895, so born ~1817/8, and Bridget died aged in 1898, aged 80, so born ~1818.

Two years after their emigration, in 1838, their single younger sister Ellen (likely born ~1820), and their older married brother Patrick (likely born ~1810-1812), along with Patrick's wife Honora and 5yo son Michael also emigrated. I have found Patrick and Honora's 1829 marriage in the NLI records for SixMileBridge, as well as the birth of their two son's Michael (1831) and John (1834 - though presumably died prior to the emmigration) but nothing else from SixMileBridge to validate the connection. Given that the Parish records only start in 1828 this is not surprising

Margaret and Bridget's death records (from the 1890's - so a long time later) both give their parents as Michael Considine and Bridget McMahon. And a number of Ancestry trees list their dates of birth as 1786 and 1790 respectively (which would coincide with a marriage ~1810 and hence Patrick's birth soon afterwards) - though I haven't been able to locate a source for these dates.

I am hoping someone may be able to suggest avenues for identifying any pre-1828 information - either on the birth of the four Considine children (Patrick, Margaret, Bridget and Ellen), or information about their parents (Michael and Bridget). This may be one of those brick walls for me - but I'm not quite ready to give up yet.

All the best,
 David