Moheb gave you the right answer before, see his post:
http://www.freehegra.com/Discussions/How-to-immigrate-to-Australia/277-Re-Other-dependants.html#277Additional Info:
Other relatives may be included in the application if they are wholly or substantially reliant on the employee for financial support for their basic needs of food, shelter and clothing and they have been reliant on the employee for that support for a substantial period.
They must also be more reliant on the employee for support than on any other person or source. A relative may also be considered dependent on the employee if they are reliant on them for financial support because they have a mental or physical disability which stops them from earning a living to support themselves.
Other relatives dependent on the employee or employee's spouse may include, for example, an aged, unmarried relative.
Dependent family members who are 18 years of age or over, should obtain form 47A and attach it to the visa application.
Good Luck,
FadeL Fawzi
http://icuimmigration.com