Correction, THREE (POTENTIALLY FOUR) different people -
Mary Clarke, wife of Patrick Clark and daughter of:
Mary Caulfield (nee Tunney) and James Caulfield and the listed addressee for the census extract
Mary Rafferty, applicant for the census extract that was sent to Mary Caulfield's address
and
Mary Rafferty born C1850 listed on the census extract and who may be the applicant or could be a relative of the same name who emigrated to England and married Michael Prendergast.
And why does everyone have to be called Mary? My head hurts...