During the student protests of 1968, the 24-year-old Heise painted some of her first works depicting interiors. Afterwards, she created many more paintings with similar themes. Mesmerised by the interior paintings of Richard Hamilton, Heise created spatial artwork of rooms with clear composition and firm definition. She began to gradually add more detail, and in 1970 she created her first portraits. Heise works slowly, creating around five oil paintings in the space of a year. She mostly uses photographs as a blueprint, but at the same time each detail feels deliberate and arranged. At the end of the 1970s, Heise became a lecturer at the University of Applied Sciences in Hamburg, which she continued doing until 2005.