The Independent Minister was among those paying tribute to Sr Stan during a surprise celebration of her social justice work over the past five-decades.
More than 200 people, including politicians past and present, frontline workers and the people they support attended the event.
Speaking at City Hall, Minister Zappone said:
“Sr Stan’s work has directly impacted on the lives of thousands, tens of thousands of men, women and children.“She has never left bureaucracy, politics or administration stand in her way. Whether working with people who are homeless, members of the migrant community or those targeted by thugs and criminals Sr Stan has shown determination, vision and courage.
“She is truly a woman warrior.
“My late spouse Ann Louise, myself and indeed the entire LGBT Community will be forever grateful for her timely and vital contribution to the Marriage Equality Debate. It came at the most important moment, just when most people were deciding how to vote.
“Sr Stan is a true hero. She is driven by a belief in fairness, equality and justice. It is only right that Dublin should gather at City Hall to celebrate her work.”