Thanks Tom & johngirl as ever you have been most helpful.
The possibiliy that Mary's mother also Mary (nee Mckie) was employed there might tie in with the fact that before she and her husband to be, Louis Avery, left for Australia sometime between 1881 and 1890, he is shown in the 1935 Australia's who's who as having been engaged in "industrial and reformatory school work in Dumfries." What it doesn't mention though is that in the 1881 census for school in Stranraer, Scotland he is shown as being an inmate! When they got to Australia they Married in Adelaide and then they went to Broken Hill - their first child was born there in 1891.
Tom thanks for your email just received and I'd like the other copies if you could send them please?
Terry