According to Margaret Cobcroft's death certificate she was aged 20 at the time of her death and was born in Scotland. She had been living in New South Wales for 18 years.
'Cobcroft, Margaret (1852–1872)', People Australia, National Centre of Biography, Australian National University, https://peopleaustralia.anu.edu.au/biography/cobcroft-margaret-24967/text33635, accessed 27 January 2023.
12 February,
1872
(aged ~ 20)
Sydney, New South Wales, Australia