Jackie Marsh was a reporter for the local paper who came to Coronation Street to get the story behind the sacking of David Barlow from Weatherfield County FC. David was sacked after sustaining an injury but manager Sid Lambert re-employed him after Jackie's article, in which the club was criticised, was published.
Initially trying to obtain further information for a newspaper article from David's brother Ken Barlow about David's early football career, Jackie and Ken formed a close friendship. Ken fancied Jackie and persuaded her to take him along to an art exhibition review. He wasn't entirely happy with Jackie's article, accusing her of writing like a "Victorian lady novelist", but he was nevertheless pleased when she took an interest in his scheme to clean the canal so that it could be used for a boating club by the Granston Technical College, where he taught. Stimulated by their discussions about art and culture, of the sort he didn't normally have with his wife Valerie, Ken started calling on Jackie and they soon embarked on an affair.
The pair were exposed by Elsie Tanner, who on one occasion saw them kissing. Elsie warned Ken to be wary of Jackie. Ken was planning to go on a secret weekend away with her, using a conference as a cover, but he then realised he'd be stupid to leave Val and his two children and told Jackie that it was over.