Who is Verona from Fairest of All: A Tale of the Wicked Queen and what is their importance?

Verona is the Queen's lady-in-waiting. She is also her best friend in the castle. The Queen considers Verona indispensable until the fateful day when the mirror proclaims that Verona's beauty now surpasses the Queen's. In her rage, the Queen exiles her friend from the land and lives the rest of her life in miserable loneliness.