As long as you deposit it in the bank in increments less than $10,000 and in irregular amounts and periods, it will not attract the attention of Austrac - they monitor all three factors. E.g. it will attract their attention if you deposit $5,000 every fortnight for the next 20 weeks. This is due to the AML/CTF Act.
You can also receive gifts of up to $12,000 per year per person as well, according to the ATO. Just say your partner and you were gifted $24,000 ($12,000 each from the father before he died) - you do need to declare this on your tax return though. There's half your problem gone already....
PS this is not advice.
I have seen some stupid suggestions on ASF, but this has to be one of the stupidest. This is illegal and is known as smurfing. And you can go to gaol.
Whilst depositing the whole amount in one go is not illegal.
http://www.austrac.gov.au/elearning/pdf/intro_amlctf_placement_techniques.pdf