Lill wrote her first play in 1979, On the Line, while still working for the CBC in Winnipeg. The play is about the strike by immigrant garment industry women workers in Winnipeg. Her next play was The Fighting Days (1985), examining the early days of the Canadian suffrage movement. Her monodrama The Occupation of Heather Rose (1987) is based on her experience in Northern Ontario. It speaks of a young white idealistic nurse who went to work on the Snake Lake Reservation. The play was nominated for a Governor General Award. Memories of You (1989) is about the controversial life of the female artist Elizabeth Smart. It was nominated for Chalmers Canadian Play Award. Sisters (1991) follows the events revolving around the burning of a residential school by a nun who worked at the school. All Fall Down (1994) is a story about the daycare worker who is charged with sexual abuse and all associated consequences.
