Getting into a good secondary school in Ireland?

We are an American family. My husband has Irish citizenship through descent; the rest of us do not. We are strongly considering relocating to Ireland in less than 2 years. I can take early retirement from my government job and have a reasonable pension. We can use other retirement funds to live off of, so working in Ireland is not essential (but we might eventually like to find some type of free-lance or odd job to do). Our youngest daughter, currently 14, is keen on finishing her secondary studies in Ireland and staying on through university and becoming a citizen. She is a stellar student who is very serious about her studies. I have written to a handful of secondary schools (from the schooldays.ie website), but have gotten little response back. This is very difficult to do from across the pond, but I am trying to establish some kind of connection or contingent acceptance before we take a trip next fall to visit schools/areas. I would like her to go to a good school; I recently wrote to Mount Mercy College in Cork. Wondering if anyone knows about this school, or has friends or anything like that. I think having her go to an all girls school could be really good, but it's not essential. No, we are not religious, but we want her to go to a school that has high academic standards that will enable her to be prepared for the university level studies. Most importantly is to connect with other families who have done this who can give us some guidance. Thanks!