Heather Martin is the wife of Jim Martin, the current union president in Vancouver.
At one point, she began a relationship and married Jim Martin. Jim then starts an affair with his long time friend, Alicia Fuentes. They eventually end things though, with both sides claiming to have not yet moved on. Alicia has apparently been meeting with Heather to ask Jim to stay away from her.
When it is revealed that Jim was having an affair with Alicia, and that she had been asking Heather, to make Jim stop pestering Alicia, Heather momentarily becomes a suspect to the murder of Alicia. Kiera eventually realizes that the one who really ordered the hit was his campaign manager, Sara Davidson, who was secretly funding Jim's campaign with the help of some large contributors that Jim had apparently been stubbornly turning away.