Hi Julie,
I don't know if this will be any help. My ancestors are descended from John McMurray & his wife Mary Donaldson. My cousin has some information on her tribal site, which has no connection that I can see to our family but it fits in with yours. She may have made a note just in case they are related through a sibling. The following is all I have been able to find.
Sarah McMurray b. abt. 1845 Armagh, Northern Ireland, died 1923 Carlton Victoria, married John Nicholas Curwood in 1867 Victoria. Her parents are John McMurray & Margaret Jennings. This information has been taken from the Victoria Pioneer Index. Vic BDM show Sarah Curwood daughter of John McMurray & Margaret Jennings d. 1923 Carlton aged 78, R/No. 13946. Sarah & John had 8 children. You can get that information from a VicBDM search.
Our family also has a Sarah McMurray b. abt. 1851. Very hard to find records from Ireland, I have added some spouses to some of the family with a ? as I can't be sure it is correct, even though the place names fit.
Sorry I don't have more, but every little bit helps so I hope it is relevant to you.
All the best,
Sue