If you ask most Celtic pagans to name the three Morrigans a good number of them, in my experience, will say Badb, Macha, and Nemain despite the fact that Nemain is never explicitly called the Morrigan or included with the other two anywhere in Irish mythology. I personally blame this one on the multitude of modern pagan books which blithely say that the above named trio are the three Morrigan, however it can likely be traced back to Hennessey’s 1870 book “The Ancient Irish Goddess of War”. Hennessey put a lot of emphasis on Nemain and included her with Badb and Macha in his discussion of the Morrigan in a way that I feel led to the later conflation of Nemain with the three daughters of Ernmas elsewhere called the three Morrigans.