Cortana is only available in the USA with the Windows Phone 8.1 update (unless you put all of your settings to United States). HOWEVER, if you update to Windows Phone 8.1 UPDATE 1 Cortana should be available to all English speaking countries as an "Alpha" stat. You have to make sure your region is in Ireland and your keyboard as either USA or UK, they're some people who say that you need to also change the "Speech" option to either USA English or UK English to have her work.