William and Bridget Kelly

I am searching for William KELLY born c1837 Galway Ireland and his sister Bridget born c1839 Galway Ireland. Their parents were James KELLY and Mary CONNOLLY/CONNELLY. William and Bridget came to Australia in 1852 (ship unknown) in the company of Mary KEANE born 1837 Milltown Malbay Clare Ireland whom William later married. I would like to find the Birth dates of William and Bridget and the marriage of their parents..Regards jhc.