Who was Marianne in the French Revolution?

Marianne was, and remains, a symbol of the French Republic. She is shown in countless representations—busts, statues, paintings—as being a beautiful, statuesque woman wearing a long flowing robe and a Phrygian cap. After the French revolutionaries executed the king, the new republic needed a symbol all of its own to represent the new France. As a result, Marianne was born. As well as representing the republic, she is also the embodiment of liberty. In fact, on the numerous occasions since the Revolution when France has ceased to be a republic, Marianne has remained as a symbol of liberty. In that sense, Marianne continues to represent an important ideal in French civic life, a shining example to which all people who desire the good of France should aspire.
https://www.gouvernement.fr/en/marianne-and-the-motto-of-the-republic