I live in an intentional community and have been asked to help homeschool one of the kids living here in history classes. I asked the kid (14yo) what he wanted to learn about and he was interested in medieval Ireland with a focus on knights, royalty, as well as some darker themes, like capital punishment. I have very little knowledge of Irish history and was planning on looking into some books to provide the material. The kid and I would then engage in critical thinking discussions around what we're reading. My hope is to approach the subject with a focus on historiography, as well as conflicting perspectives and takes on the history. Ideally, I would love several recommendations to form a curriculum for a few months!
Very roughly speaking, the historiography of medieval Ireland has been divided between pre-Norman period (From "Early Medieval", Viking Age, to the late 12th century) and post-Norman period.
Unfortunately, the primary interest of the kid in question rather focus on post-Norman period, and it is not so easy to find the good introductory study (especially pre-uni level) for that topic.
Downham, Clare. Medieval Ireland. Cambridge: Cambridge UP, 2018: is almost the only affordable (and not so physically heavy) overview that covers both periods, but I'm afraid it is definitely for OP, not the kid. The historiographical discussion might also be not the strong point of this book. As for the reference work for OP, I also find that, though a little older, A Companion to Britain in the Later Middle Ages. ed. S. H. Rigby, Oxford: Wiley Blackwell, 2003, includes the good overview essay also with focus on the historiography of each region in the British Isles (and apparently sold on sale somewhere on the internet now.....). Alternatively, as an one-volume book for the entire period, Seán Duffy, Ireland in the Middle Ages, Basingstoke: Palgrave MacMillan, 1997, is concise and good, with special focus on the 12th and 13th centuries.
As for the resource for studying materials for the pupil themselves, I wonder whether you can make use of the online resource site made by some historical museum in Ireland: