In 1917 apprenticed in engraving and textile printing with Pierre Léon Dusouchet. Marrot became a teacher and was selling some of her original textile designs when she met Raoul Dufy, a Fauvist painter, who in turn introduced her to Paul Poiret, a prominent fashion designer at the time to whom Marrot subsequently sold a dress design — and ultimately fabric for his work.

Marrot's style was distinctive for its simplicity and playfulness. She often incorporated bold geometric shapes, stylized flowers, and whimsical patterns into her designs. Her use of vibrant colors, including her signature shade of blue, added an element of liveliness and joy to her work. In 1932 her work was exhibited in the Salon des Artistes Decorateurs show came to the attention of Jean Schlumberger, an Alsatian textile manufacturer with Manufacture Steiner de Ribeauvillé. Schlumberger became her exclusive printer and a devoted friend for 30 years until his death in 1963. Together they produced over 320 fabric designs and numerous table linens.