Hi Karen,
I can see using Griffith's valuation that there are plenty of Hurleys and Sweeneys in Cork in the 1850s. One of them is an Ellen Hurley - Perhaps there is a change that this is a child or grandchild of your Eugene and Ellen? It lists her location as the "village of Clasheen" - these days spelt Glasheen, just outside the city centre. Perhaps it might be worth getting in touch with the parish to see do they have baptism/marriage certificates?
Here is the link to the page on Griffith's valuation:
http://www.askaboutireland.ie/griffith-valuation/index.xml?action=doNam…
Also worth keeping an eye on Historicgraves.com. This is a resource of digitsed graveyards around the island of Ireland. The database is always being added to so check back regularly, especially if you have particular name or place in mind. The link to the seach a name section is below. Keep in mind too that only legible headstones have been added, so if you can't see a name of interest it does not necessarily mean they are not buried there. At the moment it looks like there arent many Hurleys from that period recorded in Cork City, but that will change over the coming years as more graveyards are added.
Hope this helps and good luck with your search!
Dave