What is the reason for Fatima, daughter of Muhammad, being given the epithet "Az-Zahra," and is there evidence for this title?

Many scholars have given Fatimah, the daughter of the Messenger of Allah, peace and blessings be upon him, the title "al-Zahraʾ." The title means: the radiant, white, enlightened one. A man is called "azhar" and a woman "zahraʾ." The Prophet, peace and blessings be upon him, was described as "azhar al-lawn," meaning white with a reddish tint, which is the most beautiful of colors. This title for Fatimah is merely a description and praise of her beauty and good appearance, like her father. There is no legal evidence for it, and this title was not given to her in the favored centuries. What the Shias mention regarding the reason for the naming or that she did not menstruate is baseless and false.