Foxrock is in Co. Dublin - a rather upmarket suburb on the south side of the city, but was probably quite rural at the time your ancestor was born. I have never heard of Kinstore, but would hazard a guess that it is actually Kingstown, which was the old name for Dun Laoire (or Dunlaoghaire) which is also on the south side of Co. Dublin, further out than Foxrock. The car ferry to Holyhead in Wales sails from Dun Laoire harbour.