The name Grania is a girl's name of Irish origin meaning "grain of corn". Grania and is often added to lists like Best One-of-a-Kind Names for Girls and discussed in our forums with posts like "Harry Potter themed CAF - PART 2/3".
From the experts:
In addition to being the appellation of an ancient grain goddess, this name was also borne by two mythic Irish figures, one of whom was betrothed to legendary chieftain Finn MacCool, the other the brave sixteenth century pirate Grainne Ni Mhaille— known in English as Grace O'Malley-- whose name passed into poetry as a symbol of Ireland. Grania is popular in Ireland and possible here, especially in this Anglicized spelling.