Not sure if this is the family or not. My John Brooks was born cr. 1815 in Halley Oxfordshire. We know of 2 sisters that living in Bath at the time of his arrest(although don't have any names yet). He was send to Tasmania in the early 1840's by which time he had married a Sarah ? and have two children ( girls we think). His convict records didn't have much info on them.
Ring any bells?