Just some advice from the boffins please.

My mother in law passed away last week (27-07-2012) intestate and I have to sort a few things.
She got a pension from the government.
Am I correct in assuming that the pension up to the above date is still payable ? In other words they pay in arrears and not up front.
Should I wait till they have paid into her account before I notify them of the death ? I am fairly sure that if I do it now before the end of the month, they are not going to pay for the portion of the month that she was still alive.
Also , the bank needs to be notified and to the best of my knowledge, they will freeze the account.
At what stage will the bank balance become available again ? Remember "intestate", so no lawyers needed.
Some advice will be appreciated.