She is connected to land, her “home” being a cave in the hills of Ireland 
(this kind off the top of my head & also as I’m get kind of settled for the night) but also the sea & sky.
In Irish lore, stories, & beliefs… the 3 realms are Earth, Sea, Sky. Her reference as a Triple Goddess in their history & culture isn’t one that sees a triple goddess in Maiden, Mother, Crone form. That reference to a Triple Goddess is of a neo-pagan spirituality & belief system. Its more a goddess with 3 different aspects such as 3 sisters whether with the same name or otherwise. (IE: Brigid, however she also multiple qualities)
The Morrigan is 3 sisters (La Morigna I may have spelled it wrong, but its the plural form) or as the singular the Morrigan.
They each have some similar but also very different representations at the same time.
So it would depend on how you work with her as far as labeling her with a maiden, mother, crone aspect. Also how true to her & her history, lore, & culture as well as how she is represented & honored from her origins through Ireland.
Its funny that this showed up 1st in my feed when I popped in because since I originally made the post, I have learned so very much more & in depth. I was just thinking that this needed to be updated a little bit from this to include resources & source material 