Thank you. since i posted my query I have discovered that my great grandparents, Alexander Stewart McIntyre and Eliza Cooper were married in Rosario St Bartholemew's Anglican Church in 1881. It would seem that Eliza returned to Ampney Crucis (where she was born) to have her first child, also Alexander Stewart McIntyre (my grandfather) in 1882. She must then have returned to Argentina as the record shows that a second son, William was born there in 1884. Unfortunately I have not been able to trace emigration/immigration records for this period as they are only available after approx 1890. I suspect that Mabel McLean was either born in the Argentine or emigrated there sometime between 1880 and 1890.
Regards
Bruce