Palmer from CO Cork Ireland

My maternal ancestors are Palmer, Richard, from Cork, Ireland, married to Catherine, maiden name unknown.

They had several children, 2 died.

Richard Palmer and Catherine`s children:

Eliza born May 8 1820 died Jan 5 1830 St Helena Island, South Atlantic.
Margaret born August 10 in 1819 St. Helena.
Richard June 25 1822 St Helena.
William May 31 1818
Isabella born October 8 1824
John ? Buried May 7 1826
Lucy 1860
Mary 1850

Does anyone have any Australian connections?