After courting for years, she and Aldarion married. Though Erendis resented it, Aldarion insisted on continuing with his voyages to Middle-earth, causing a rift between the two. Erendis took their daughter Ancalimë with her and went to live on her own on her farm. When Aldarion returned, he demanded to have his daughter returned to him, which Erendis did grudgingly, but her pride kept her from returning to him.
The partial story of Aldarion and Erendis can be found in Unfinished Tales, (ed. Christopher Tolkien). Though the actual story was left incomplete, the book does give some hints on how it continued.