Hi Rhonda, thank you for your reply and interest.
This marriage to Edmund Hughes appears to be a distinct possibility, as quite a few pieces seem to fit. The birth of the first two children in Victoria seems to be in order with what I have found so far. Up until 1853, it wasn't required to register marriages with the government in Vic. as most records were kept by the churches, and those that were registered were under the NSW Gov.
Also, I had a look at TROVE and found a some interesting articles on both Edmund and Annie.
The info you have found Rhonda, gives me some more clues to continue on with. I appreciate your help
Annie's birth date is a little different to what I had, but I'm not putting a lot of weight on that fact. On checking the death record for Annie Hughes d. 1882, I notice there are no parents names listed. This is understandable, as I believe her mother Mary and 2 siblings died of typhus in 1839, and she and the other sibling went with another family who arrived on the "John Barry". Her father Duncan went off on his own, so the informants of her death may not have known her parents name.