Advocacy by other agencies 

Anglicare's Social Policy and Research Unit has released its report, Caring for a Child with Intellectual Disability and Challenging Behaviours , which also includes an exploration of the impacts on siblings and their needs. It recommends that 'separate assessment of carer and sibling needs should be undertaken'.
Families Australia has followed up the RANZCP work (see below) by running focus sessions with adult siblings. The document Towards improved recognition and support for siblings of those with a chronic condition: A report on consultations explores the issues and sets out some directions for the future.
Addressing the needs of siblings of children with disability or chronic illness, Position Paper 69 by the Royal Australian & New Zealand College of Psychiatrists, 2011. This also includes a link to a longer Issues Paper, and includes the list of over 70 organisations that endorsed the Statement. The Issues paper can be accessed separately here
Report of the Inquiry into the Mental Health and Wellbeing of Children and Young People in Western Australia, by the Commissioner for Children and Young People, 2011. Siblings are referred to on page 87.
The Listen to Children Report finds that despite ratifying the United Nations Convention on the Rights of the Child in 1991, Australia has not effectively incorporated human rights into policy and legislative frameworks to nurture and support children. In the discussion on Basic Health and Welfare in Theme 6, Children with Disabilities, the report states: Effective support for the family environment will mean that the rights and needs of siblings of children with disabilities should also be considered. These children often experience higher rates of depression whether or not they have roles as carers in the family. 
Improving the mental health of infants, children, and adolescents in Australia, Position Paper of the Australian Infant, Child, Adolescent and Family Mental Health Association, 2011. Siblings are referred to on page 20.
National Action Plan, prepared by Families Australia (with Siblings Australia), as part of its election proposals to the Federal government in 2010. Unfortunately the proposals were overlooked.
A joint submission to the National Disability Strategy by all the State Commissioners for Children and Young People, and Child Guardians, 2008. Siblings are included throughout.