Sorry I didn't reply early. It was late here when I posted.
The marriage is for Maria (Mary) McGrath, an Irish Famine Orphan who was sent to Melbourne Australia on the Pemberton in 1849. The Irish Famine Memorial website has her native place as Roscrea, Tipperary but Mary has put her birthplace down on her marriage certificate as Golden, Tipperary. I believe she came from the workhouse in Roscrea immediately prior to her emigration.
Mary's age on the marriage certificate is 22 making her birth about 1831 though the Irish Famine Memorial has her age as 14 years on arrival in Australia making her birth year about 1835. Just to make it confusing, her employment records (from the same site) says she was 16 not 14, making her birth year about 1833.
Her death certificate has her age as 88 in 1921 making her birth year 1833. Though there are a couple of mistakes on her death certificate - the witness being the undertaker and Mary having died from senile decay and heart failure - perhaps not surprising. For example, her father listed as James McGragh. Interestingly, her mother is listed as Mary Duggan, which looks nothing like what is on her marriage certificate but perhaps sounds something like - throw in an accent and this is how it comes out? And it just says she is born in Tipperary.
The marriage took place on 4 August 1853 in Melbourne to Timothy Aherne.
I don't have any other information about Mary. Certainly nothing about siblings.
I've attached the full clipping for the marriage certificate to compare with other examples of handwriting.
I was thinking that Donaghue was probably the closest but I'm just not sure and can't find anything so far to match a marriage or baptism matching that name. It may just not exist. O'Donaghue or Monaghan are interesting variations which I shall check out.
It's early here and I'm heading off to work so I apologise now as I won't be able to respond to any queries until later tonight.
Thanks, everyone, for your help so far! It is certainly a tough one.
