She was the daughter of an Anglo-Saxon King of Kent. She refused a marriage to a pagan prince and founded the first nunnery in England.
According to Wiki, Eadbald, her father, was the first Anglo-Saxon King to convert to Christianity. This seems almost certainly false, however, as Ethelbert, Eadbald's father and also King of Kent, was the first Christian convert. Eadbald seems to have had an on and off relationship with Christianity.
This is a very frustrating time in English history as sources are few and it is very difficult to trace the Anglo-Saxon migrations and how they interacted with the Britons. Plus, there are several legends that may or may not be true.