Why did Grace O'Malley turn to piracy?

Grace loved the sea ever since she was born. She wanted to sail with her father on sailing trips, but was discouraged because she was a girl. So she cut her hair and dressed in boy's clothes to proved she was good enough to go. Then her family nicknamed her "Grainne Mhoal" or "Bald Grace". Nevertheless she went on the trip. Soon she married and at the time a lot of fighting was going on at the time. Her family was going bankrupt, so she turned to piracy. She like this way of life, so she kept living like this for a while.