Mick, it's a bit like the difference between learning a tune from a book and learning from the living tradition. One might be the ideal solution, but that doesn't rule out the other as totally invalid.
I don't think anyone expects Americans to reproduce perfectly the sounds of any precise dialect of Irish, but I imagine many would like to be able to construct an approximate equivalent from the range of sounds that they can comfortably use.
Hence, guidance on major distinctions like whether a C is pronounced K or S is useful, as your daughter will be aware. It's particularly useful for parents contemplating a choice of name for their offspring.
When anyone on Mudcat or Chiff and Fipple asks for advice on Irish pronunciation, I try to give the most foolproof advice I can, but am conscious that the same attempted "phonetic transcription" may be picked up differently by people in differnet parts of the world whose accents in English may vary considerably. I'm also aware that there are several people who have much better Irish than I have, but they may not always open the threads where these questions arise. I mentioned the two possible pronunciations of Siobhán as an illustration of that there are variations in pronunciation (OK, maybe I was asbestos-coating myself against a flame from someone who learnt a different pronunciation).
And by the way, I shouldn't have limited myself to the Vancouver-Germany region, I unthinkingly overlooked several Mudcat stars from the other side of the globe (they know how they are!).