Hi,
Thanks for your message.
Brein is an unusual surname. I did a search for it in the land records pertaining to Ireland in the 19th century. These don't have any genealogical information but can sometimes be used to tie a person to a specific place. Here are the Brein?s in the earlier Tithe Applotment Books:
http://titheapplotmentbooks.nationalarchives.ie/search/tab/results.jsp?surname=brein&firstname=&county=Wexford&parish=&townland=&search=Search
There were none recorded in the later Griffith?s Valuation (1848-64)
http://www.askaboutireland.ie/griffith-valuation/
If the couple were married in 1864 there should be a civil record of it as this is the year that civil registration became mandatory. Perhaps you may be able to find the record which will give you a more specific place name. Civil records are available from the General Register?s Office. Here are their contact details:
General Register Office
Government Offices
Convent Road
Roscommon
Ireland
Tel:+353 90 663 2900
Locall:1890 25 20 76
Fax:+353 90 663 2999
Homepage: http://www.groireland.ie/
You can search the indexes to these records up to 1958 online at:
https://familysearch.org/search/collection/1408347
The Irish Times website shows clearly where particular surnames were recorded in Ireland in mid-19th century. If you follow the link below you will see that there were not Breins recorded, however on the right hand side of the page you will see variants of the name. It may be useful to keep these in mind as you do your research:
http://www.irishtimes.com/ancestor/surname/index.cfm?fuseaction=Go.&UserID=
Best of luck with your research,
Genealogy Support