The Scottish Eileen was a midcentury darling that was on a long downward slide for decades. And then, in 2012, it took an unexpected pivot and has been inching upward in the US. The unrelated but similar-sounding Isla may have revived the taste for Eileen. Isla along with Lee and Lena might be nicknames for Eileen. Eileen is an Anglicized form of the Gaelic Eibhlin or Aibhilin, which is technically a form of to Evelyn/Aveline, but is also sometimes considered part of the Helen family of names. Aileen is the Irish version, less popular now than Eileen.

Ferelith is an unusual yet deeply-rooted Scottish girl's name, also found in ancient Ireland and drawn from the Gaelic Forbhlaith or Forbflaith. While it went through a period of dormancy after the Middle Ages, there are some modern women named Ferelith, including actress Ferelith Young and Princess of Denmark Anne Ferelith Fenella Bowes-Lyon.