Are there any passenger lists for ships to Australia, probably New South Wales, in the period 1850-1855?

I am looking for information about Margaret Agnes Anne GREEN (known as Agnes), who is said to have travelled on the "Countess of Harborough".

She married first William WILSON, and may have travelled with him from the Cape Colony in 1852 or thereabouts. Thir first child, Caroline, was born in Sydney on 20 April 1854, and the second, Emily, was baptised at Braidwood, in southern NSW, in October 1855. William Wilson drowned in the Tuross River in April 1855, and Agnes WILSON married Alfred John Dawson FRANCIS in Moruya, NSW on 9 January 1858.

I am also interested in knowing whether Afried Dawson FRANCIS travelled on the same ship, and who was with him. He may also have travelled under the name of Alfred Francis DAWSON.