All that can presently (September 2025) be gleaned about Elsie Wales from sheet music covers and by Internet searching is that she was presumably an American sopranor who has been featured on 4 works published between 1912 and 1913.
Her portrait on the left together with Mabel Williams is taken from You're a Great Big Blue Eyed Baby (1913) music by A. Seymour Brown, and published by Jerome H. Remick & Co., New York & Detroit, USA.
Make Me Love You (1913) music by George W. Meyer, words by Jack Drislane and published by F. B. Haviland Publishing Co. Inc., New York, USA describes them as Two Singing Girls with Eva Tanguay's Vaudeville Co..

Variety (May 7, 1910) published the following advert headlined:

3 SINGING GIRLS 3 Soprano, ELSIE WALES. Contralto, MABELLE MEREDITH. Mezzo, EVELYN ELLISON. Dainty, Vivacious and Refreshing Harmonists la a Repertoire of Delightful Melody. Extra added feature S.-C. Crcuit.
Those 'Three Singing Girls' (Elsie Wales, Mabelle Meredith and Evelyn Ellison) are the attraction that makes the pirogramme at the Grand Theatre worth while thls week. These young women are not only sweet vocalists but they are also sweet appearing. They have style, grace and beauty; they are dainty and demure. They sing popular airs so pleasingly that the audience demands several encores.
Sacramento Bee.