Thanks for your help Wivenhoe and Debra. I can understand why you want to know how I am getting my information but I can reassure you that my information comes from news articles found in Trove, and old newspapers, and from what I find in Linc Tas State Library. I go into the Archives section then type a name in the 'Tasmanian name index' to see what I can find and it also takes me to articles of interest. Other avenues have been through Findmypast, Heritage, the Diggers Index, Ancestry and looking through Archive library books.
It is true to say Wivenhoe that Bridget was 20 years when she arrived in Hobart 16 September 1854 on the Maitland ship.(Tasmanian Genealogy Mailing list-Tasmanian Immigrant Ships). This is the Bridget I simply have been following as it was mentioned that she came with the Gibton family. Through her research Dr Susan Chamberlian came across the three children born to a Bridget Elizabeth Murphy in Elizabeth Street and a Mrs Gibton senior was with her at the time. The father's name is stated as Charles Bayley Mariner. I have looked into the Gibton family through Linc Tasmanian State Library under Tasmanian Index to get some idea where Bridget and her sister Ellen went. I found through Linc that Bridget was to work for a Mr Kennedy in Launceston for 12 months. Ellen went to work for a Mr Dodery for three months and married a James Wall 17 April 1855. Next I see a Bridget Murphy (going by the news article Trove: The Mercury Hobart (Hobart Tasmania 1860-1954; Thursday 22nd February 1866 p.3) Where a Bridget Murphy gives evidence at a baby's inquest. I agree, she would have been in her 30s by now and would not be described as a 'girl'. It is quite possible that I could have been following the 'wrong' Bridget being that it is such a common name and there were many of the same name during this period. Researching a particular person or family, is not an easy task and there are often many 'brick walls' to break. It is important to keep an 'open mind' until it is certain with birth/marriage/death records/certificates and news articles tell us otherwise. I have found another Bridget Murphy aged in her 20s in this news article again found in Trove: City Police Court, Wednesday 31st March, 1873 where a Bridget Murphy was found having on the 11th March guilty of using abusive language to 'him' (no name of the man) in Collins Street, and spitting on him. It was shown that she had done this to him several times all because he had stopped payments which he previously paid through a constable of law. This could be a 'possible' Bridget? The records of the birth of three children you can find under the Names Index Tasmanian Archives through LINC. I know this is going to be a long journey to find my Bridget so I shall keep on keeping on until some 'light' shines on 'what could be my Bridget". Thanks for your help