One night, while Connor was absent, she witnessed Ramirez's death at the hands of another Immortal, The Kurgan. After the Quickening, The Kurgan raped Heather but she kept this a secret from Connor. In 1555, Connor was warned that his mother, Caiolin MacLeod, was to be killed by the Clan MacLeod. Heather expressed her disapproval to Connor's clansmen, not understanding why they could not leave Connor alone.
She sometimes suffered because she grew older while Connor did not. One night she cut a piece of hair and gave it to Connor saying that at least that piece of hair would not grow old. She never bore any children and died in 1590. She asked Connor to light a candle and remember her on her birthday, which he did.