Sister Mary Frances Wangari Sebastian, LSSJ, is a Kenyan-born Religious Nun and member of the Little Sisters of St. Joseph. She began her work for the poor in 1992, encouraging youth to say no to FGM and continue their education.

She has been in various forums for interfaith dialogue, executive member of the catholic justice and peace commission for 8 years as an adviser. She currently serves as the director of the Justice, Peace, Integrity of Creation Franciscans Africa (JPIC-FA) office in Nairobi, Kenya, where she has brought tens of thousands of youth together for peace building and conflict management. She has also organized a national Interfaith Youth Forum on Environment and Peace annually since 2014.

Sr. Mary Frances has worked with Franciscans International to implement trainings on 'Making Human Rights Work for People Living in Extreme Poverty' and advocated for the Mukuru slum to reach the status of Special Planning Area by the Kenyan government. She has trained Franciscan Justice, Peace and integrity of creation Franciscans Africa (JPIC) Animators on rights-based approaches to advocacy, held a peaceful electoral campaign, provided emergency response to the needy, and offered interventions to avert the crisis of youth radicalization in Kenya.

Sr. Mary Frances has also been an acting National Coordinator of the Association of Sisterhoods of Kenya's Justice and Peace Commission (AOSK-JPC) and before then she was the deputy National coordinator and  worked on civic engagement on the making of the Kenyan constitution. She has trained women peacemakers, human rights defenders, and emergency response, and has facilitated forums and planned events for International Women's Day, World Peace Day, and International Human Rights Day.  

Interfaith Dialogue, Sr. Mary Frances was named an environmental steward champion by United Religions Initiative and recognized by the Franciscan Family Association Kenya for promoting Justice, Peace, and Integrity of Creation. She is a permanent mentor of youths on peace building, leadership, respect of human dignity, and a clean, greener Kenya through environment initiatives.

In addition to the above, Sr. Mary Frances is currently the Executive Director of JPIC Franciscans Africa, an office belonging to the Franciscan family Association that began in 2007 after a world social forum. She believes that her work is motivated by the call of prophet Micah 6:8, which asks for justness, love, and obedience.