It's funny you mention that. My older and just younger sister have developed a love of Celtic music, as I have, though we all came to it seperately and without the others knowing about it. Our maternal grandmother was Irish, but she never talked about her Irish roots; I'm not even sure when her family came over. Her paternal grandparents, the Selbys, were from Kentucky and her great grandfather was a colonel in the Confederate Army, but I'm not sure about the maternal side, the Dolans. I don't think anyone in our family ever asked her about or did any sort of search.
My younger sister loves to go to Celtic fests and Highland games, neither of which I have ever done. Living in MA, I could avail myself of some live Celtic music, but I just don't feel like schleping into Boston!