Blue text around an illustration of a woman's head wearing a red hat on a white background
Western Badge L A / Anaheim
This is most likely a promotional button for Thoroughly Modern Millie, a 1967 American musical film starring Julie Andrews. The story focuses on a woman who intends to marry her boss. The film was nominated for seven Academy Awards and five Golden Globes. “P.S. I love her” is not a phrase used in the film, though the theme of the movie is about love being more important than money.