Delia is a teenage girl living at Seacliff and appears at the start of Book 5. She is daughter to the lady (Edwina) who looks after the Ranger's house and is married to the inn-keeper there. Delia develops a friendship with Will and has a crush on him, but any hopes of a relationship are dashed when Alyss turns up at Seacliff and Delia realises that there is something special between them.

There are hints that Will may have had feelings for Delia as he seems disappointed when he finds out at the end of Book 6 she is married to the ferryman's son, Steven.