[1] She is best known for the song "What A Difference A Day Makes" (originally "Cuando vuelva a tu lado"), which was popularized by Dinah Washington and has been covered by numerous artists.

In 1907, the then 22-year-old de la Portilla married Leo A. Grever, an American oil company executive, and in 1916 became a U.S. citizen and moved to New York City, where she lived for the rest of her life.

[1][2] Grever wrote more than 1000 songs — the majority of them boleros — and her popularity reached audiences in Latin America, Europe, and the United States.

[3] Grever once said: "I had to leave my country, and now in New York, I am interested in Jazz and Modern Rhythms, but above all, in Mexican Music, which I long to present to the American people.

[4] Other hits continued to follow, such as "Volveré" (I Will Return); "Te quiero dijiste" (I love you, you said), written for the 1944 Esther Williams film Bathing Beauty, as well as "Cuando vuelva a tu lado" (When I Return To Your Side as recorded by Nestor Mesta Chayres)[5] and "Por si no te vuelvo a ver" (In case I don't see you again).