Mary,
My goodness, how busy you've been on my behalf! And thank you so much for all this wonderful information, bringing the City of Cork of the early part of the 20thC gloriously to life again. I had a family holiday in the area (stayed at a B and B in Blarney) a couple of summers ago. A pity I wasn't on this line of enquiry then, as I could have had a good look around Cork City myself, as well as visiting the archives there.
Anyway, those links you have provided are fascinating, and I have a much better idea now of the geography of the place 100 or so years ago...
Very best wishes, keith
NB Forgot to answer your last question, and yes I did find a couple of family members that I was searching for at 5, Hillgrove Lane, but none of the bride's family at 5, Walsh's Lane...K