Gráinne O'Malley (Irish: Gráinne Ní Mháille, pronounced [ˈgˠɾˠaːn̠ʲə n̠ʲiː ˈwaːl̠ʲə]; c. 1530 – c. 1603), also known as Grace O'Malley, was the head of the Ó Máille dynasty in the west of Ireland, and the daughter of Eóghan Dubhdara Ó Máille. Upon her father's death, she took over active leadership of the lordship by land and sea, despite having a brother, Dónal an Phíopa Ó Máille. Marriage to Dónal an Chogaidh (Donal "of the war") Ó Flaithbheartaigh brought her greater wealth and influence, reportedly owning as much as 1,000 head of cattle and horses.
https://en.wikipedia.org/wiki/Grace_O%27Malley