Who is Erendis from Unfinished Tales of Numenor and Middle-earth and what is their importance?

Erendis is the wife of Tar-Aldarion in "Aldarion and Erendis: The Mariner's Wife." She spends her life fighting for her husband's love. He is pulled by his love for her and his love for the sea. Eventually, he leaves one time too many. Her pride will not allow her to forgive him. He can force her to send her daughter to live with him, but she will not join them. Erendis lives out her life alone, cut off from all who once loved her.