Frances
Have done a bit more research and have abandoned the idea that she was only 24 when she died.
Mary Ann is a possibility, though the name Mary is never mentioned again.
Margaret Curphey did marry a John Cretney.
What intrigues me is how did a fisherman who was living with his mother in Peel in the 1851 census, come to marry a girl a few months later in Onchan. It is an extracted record so I presume this meant the actual church and not the Parish