William and Margaret Fitzgerald ex Co Cork Ireland

[Abygail]

I'm working on a very long process of elimination here.   
In my tree I have a William Fitzgerald b c 1815, allegedly his father was a Publican, after painstakingly trying to trace him given the details on his death certificate I have decided that his history has been a white wash to hide his true history.i   So I am trying to identify which of several dozen (at least) who came to Australia may be him or possibly a father to him.
The above pair are husband and wife who, along with 3 of their 6 children arrived into Sydney in 1833.  William Fitzgerald was transported for 7 years to NSW at the age of 50 years.  He sailed on the Java, and according to the scarce records allegedly his wife Margaret and 3 of their children (I'm guessing the younger ones or the unmarried ones perhaps) also came out with him as 'Free Settlers'.  His profession was given as a Brewer.
I'm hoping readers may be able to give me some useful hints or even data relating to this family.
Thank you.  Aby

[LH]

Hi

Website http://members.pcug.org.au/~ppmay/cgi-bin/irish/irish.cgi
gives William's place of birth as Limerick, so this may be where to start a search, unless you know otherwise.

Regards

[Abygail]

Thank you for that, what I'm hoping for is someone else can confidently tell me that they didn't have a son named William born between 1815 - 1825.  Or yes they did but have no idea as to what happened to him.