Lost in limbo for decades and decades, Elsa now stands a good chance of following along in the progression from Emma to Ella to Etta, having just about lost her German accent--and as the ice queen heroine who "Let It Go" in the wildly popular Disney movie Frozen. The name shot all the up to Number 286 (its highest ranking since the 1890s) in the year after the release of the movie, though it's now fallen off a bit.
Elsa came into English-speaking use in the nineteenth century, boosted by Wagner's operatic bride in Lohengrin—the first to walk down the aisle to the famous wedding march. For a while Elsa took on a leonine image via the lioness in the popular book and movie Born Free, but that's all but forgotten. Elsa has lots of varied and interesting human namesakes, including designer Schiaparelli, writer Morante, Bride of Frankenstein Lanchester (born Elizabeth).