Weir of Northern Ireland

Hi am looking for more information on my ancestors the Weir's who immigrated to Australia from Ireland in 1864 or 1866.

They were
Joseph Weir
Birth 21 January 1836 in Belfast, Ireland
Death 01 July 1904 in Maclean, New South Wales, Australia

He married
Annie Davison
Birth 1840 in Ballymena, County Antrim, Ireland
Death 14 February 1901 in Broadwater Creek Lawrence

The marriage was 19 Mar 1864, St. Matthews Church of Ireland, Shankill, Belfast.

Looking for information about their immediate family and in particular their parents, the only information I have is I believe Annie's father's names was Thomas and Joseph's fathers name was William.

Any further information on their families would be greatly appreciated.

thanks