Hi and welcome to the Forum.
I'm not so sure this is going to be easy. Assuming your partner has an Irish passport, she has the right under the Common Travel Area agreement between Ireland and the UK to live and work in the UK; you, unless you have a British/Irish passport, may need a visa; please follow this which will take you to the UK Gov website that has the details.
If visas are not an issue and to answer your question. I lived in Lisburn and worked in Dublin; it's a beautiful country; however, to pretend that the sectarian issues of the past no longer exist would be foolish. There are still areas festooned with either Loyalist or Republican Nationalist flags, murals, and kerbstones painted in either red/white/blue or the Irish flag colours. The Protestants still parade April > August every year, they call it part of the culture, others find it offensive and although on a much smaller scale, the Republicans do the same thing.
Regardless of the reality, or your desire for your daughter to grow up in a peaceful environment, If you are a practising Christian, then you will be tagged as being sympathetic to one side or the other. You have access to UK TV in the south, you must have seen/heard the local news when sectarian issues raise their heads, they're not making it up, that's the reality of Ulster today.
I hope this helps.
Cynic
Expat Team