Marianne Brockwell is a graduate of Edith Cowan University and former school teacher and director and chairman of Western Plaza Hotel Corporation Pty Ltd, a company she established with her late husband Maurice John Brockwell in 1974.

In addition to her position on the PMH Foundation Board, Mrs Brockwell is Chairman of Torchbearers for Legacy, a charity dedicated to the widows and children of deceased servicemen.

She is an active member, sponsor and Board member of the Irish Australian Heritage Association and the Irish Heritage Scholarship Foundation. She is also an active member and sponsor of the Special Air Services Regiment.