If a parent that provides complete financial support for their family dies and willed their estate to family members and not their wife or children, what happens if this family lives in Australia?
Do you mean to other family members, as the wife and children are family members?
The wife and children all have grounds to contest the will. This needs to be done very quickly, so get legal advice immediately. This must happen straight away to prevent the distribution of assets according to the will.
Depending on the value of the estate, the wife and children will be able to claim at least a reasonable part of the estate. If the value of the estate is small, the wife would be able to get all of it.