Kudos to Rev Albert Buhagiar, parish priest of Siggiewi, for replying within three days to my email requesting the baptismal record of Nicholina Magri, from which details I was able to acquire the name of TARGET 3, wife of Saverio Magri.
For completeness, here is the complete correspondence:
Dear Rev Buhagiar (or assistant)
I would greatly appreciate your small assistance in helping me compiling my family tree upon which I have been working for the past 10 years.
I only desire the name of the mother of Nicolina Magri ( my great-great-grandma), born in Siggiewi in circa 1862 to Saverio Magri.
I suppose the mother's name can be acquired from the baptismal record of Nicolina Magri of 1862 in your parish records. I thank you whole-heartedly beforehand.
Your brother in Christ
to which the reply was
From the Parish records it resulted that Nicolina Magri was born on the 7 December 1861. her parents were Saverio and Rosa nee Grech.
I hope this satisfies your research.
This leaves only two more ancestors to meet my challenge of finding all GGGGreat parents on the 10th anniversary of my commencing my genealogical research.
These two ancestors will both be investigated at the Mdina Parish records which contain all Rabat records prior to 1902.