Ailsa owns the local general store and befriends the Fletcher family when they arrive in Summer Bay. She has heart of gold and has caring nature and sees the good in Bobby Simpson (Nicolle Dickson). Alf Stewart (Ray Meagher) takes an interest in Ailsa and they soon become engaged. Alf's daughter Roo (Justine Clarke) takes a dislike to Ailsa and feels she is trying to replace her late mother, Martha (Alison Mulvaney) and has her aunt Morag Bellingham (Cornelia Frances), a lawyer, do a background check on Ailsa. Roo learns that Ailsa served time for murdering her abusive father but most of the bay side with Ailsa. Ailsa and Alf marry in a low-key ceremony and they later foster Bobby together. Alf is upset when he thinks that the only reason she married him was to give Bobby a home. After selling her store to Alf's sister Celia (Fiona Spence), she goes into partnership with Bobby in the Bayside Diner. Ailsa later discovers she is pregnant and gives birth to a son, Duncan (Alanna Ellis) in 1989. She suffers from post-natal depression shortly after Duncan's birth and attempts to smother him at one point. However, when Duncan is hospitalized due to an allergic reaction to an old christening gown, Ailsa finally bonds with the child.