Australian answers only. I need some advice on wills and estates. Or succession , can anyone help?

My eldest sister has been appointed executor of my sisters will who passed away last week. First of all I want to know what the first thing she has to do is. Does she have to wait to get the death certificate before anything else can be done. Also if my two youngest children have been left most of the estate which would be quite a large amount and as they are only 11 and 6, can I request that she (the executor) be changed from being trustee. My sister that passed also left her son (executor) who is 34, her vehicle in the will. The day of her funeral, she (the executor, his mother) let him take the vehicle home with him even though it has not been signed over to him. What should have she had done. I am thinking of fines, insurance, what if he has an accident, third party insurance etc etc. Also, how do we divide the household and personal items if my sister stated in her will that it is to be divided up between the remaining siblings and parents and we have to sort out who wants what. How does that work. Any other info would be helpful as my eldest sister (the executor) has gone home to visitors from o'seas and just left everything up in the air so to speak. Shouldnt she be lodging court docs or something.

Steve K , she passed away in Qld

These things differ from state to state so, before we can help you, we need to know where in Australia your sister passed away.

OK - in Qld, you will need to abide by the provisions of the Succession Act 1981 at http://www.legislation.qld.gov.au/LEGISL...
Given that you say there could be large amounts involved, it is best that an application to the Courts be made for "probate". This grant of probate by the Court is the official recognition that the person to whom probate is granted can deal with the deceased's affairs - it's basically proof to the outside world that the person can sign documents, etc to pay debts, sell property, or anything else the deceased could have done.
As regards the car, by s.45(1) the car, at the moment, is legally the property of the executor (obviously held on trust for distribution). Any fines, etc. will come back to her. What she needs to do is obtain probate and complete all the documents necessary to transfer the car to him.
As to personal items, it's really up to surviving family to try to come to some agreement as to what they each want.
If the executor is not attending the affairs properly, you will need to make an application to Court that a grant of probate be made to someone else.

There's a lot of paperwork surrounding all this and it really is a matter where you need the assistance of solicitor. The money spent on this will be worth it in the long run to make sure your sons get all they are entitled to.