I believe in times of financial trouble for a Country those countries who have the ability to lend a much needed hand of assistance would be wise to do so, it will help improve relations later on and it will prevent what crisis that is happening in Ireland to not spread to other nations.
No, the Great Britian is having a lot of trouble right now with their economy to, and that they need to focus on what is happening in their country before they run and try to help the Irish get all of their financials all back to that it needs to be.
Ireland has been politically and financially independent from the Great Britain for over 70 years, They have been through periods of great prosperity since that time, and the current problems are entirely of their own making. Great Britain no longer owes Ireland any special treatment, and the country should sort their own problems out independently.
Ireland stands on its own and does very well, especially considering that it is such a small country. Comparatively speaking, one can even suggest that it is doing better than Great Britain as a whole. So no, I don't think Great Britain should help support the Irish economy at all.
My understanding is that Ireland wants separation from the United Kingdom, so I would say that they should be supported in that and it should be allowed. With that however, they need to realize that Great Britain won't being supporting their economy and they shouldn't have to. The Irish should take care of their own economy.