She is mentioned in 2 verses:

Verse 2:
Tá Gráinne Mhaol ag teacht thar Sáile

And in verse 3:
Gráinne Mhaol agus míle gaiscíoch ag fógairt fáin ne Ghalla

But the song is about the anticipacion of Irish men and women returning to rout the Stranger, not about Grace O'Malley.

Brían. I have searched the forum for any relationship between these 2 songs, and have only found one reference to Martin Ryan saying that he thought the melodies were the same.