I'm pretty sure that this name's modern popularity stems from Alec Baldwin and Kim Basinger using it on their daughter. It was used as a name before that, but it was very rare prior to them using it. Also, it isn't considered a name in Ireland, and as other people have said, it would probably be considered ridiculous over there.
This name is actually an older coinage from the 1800s. It was used in America in cities in which the Irish population was growing rapidly. It was used as a nickname, and on males not females.