Remembered for several songs co-written with her one-time husband Noel Regney, Baker is perhaps most famous for her contributions to the Christmas carol "Do You Hear What I Hear?" (composed in 1962) and the popular song "Rain Rain Go Away."
Born to Jewish parents Mark and Rose Shain, she grew up in Brookline, Massachusetts, as the next door neighbor of future United States President John F. Kennedy. In her younger years, she performed with her siblings Thelma and Esther as a member of The Shain Sisters trio.
After her two-decade marriage to French songwriter Noel Regney ended in the early 1970s, she married William Baker.
She wrote the 1961 James Darren hit "Goodbye Cruel World."