And then I acquired the February 1962 edition of Seventeen magazine, which featured very similar coats.
So what is the difference? The trapeze silhouette is narrow at the top and wider at the hem, almost triangular in shape. The A-line silhouette is defined as being narrower at the top, flaring gently wider toward the bottom. The babydoll dress is defined as having an empire waist and loose, A-line skirt.
By whatever name you call it, it's adorable, inspiring fashion!