Dr. Osborne Jelks' first environmental-related job was with the United States Environmental Protection Agency as an intern in 1994, where she worked for the Superfund and Hazardous Waste Division on remediation projects, conducting outreach and helping identify ways to clean up the sites. She cites that the role challenged her to consider her role as a community member and government employee. However, Dr. Osborne Jelks realized she wanted to work more at the grassroots level. During undergrad, she also interned with the National Wildlife Federation, where she would move to work after graduating. Jelks has worked with the NWF for over a decade in various positions. In 2002, she started at the company as the National Leadership Development Coordinator (2002-2005) before being promoted to Manager of Community and Leadership Development Programs (2005-2011). She was then appointed as Manager of Education and Advocacy programs (2011-2016). While at NWF, she co-founded the Atlanta Earth Tomorrow Program, a leadership and environmental education program focused on engaging urban youth in environmental challenges. Since its inception, the program has reached over 2,500 youth. Afterward, Dr. Osborne Jelks joined Agnes Scott College as a Visiting Assistant Professor of Environmental Health (2016-2018) and Director of the Graduate Certificate Program in Evaluation and Assessment Methods (2017-2018). Dr. Osborne Jelks works as an Assistant Environmental and Health Sciences Professor at her alma mater, Spelman College, as of 2018.

Dr. Osborne Jelks is a graduate of the Institute for Georgia Environmental Leadership and Leadership Georgia, highlighting her commitment to cultivating leadership in the environmental field. She previously served as an Advisory Board Member for Westside Communities Alliance and a Member of the National Environmental Justice Advisory Council. She has also been involved with the Environmental Leadership Program (ELP) since 2003, working to support young professionals in the environmental field. She is the Co-Founder and Chair of the Board of Directors of the West Atlanta Watershed Alliance. Moreover, she is a member of the National Society of Black Engineers, where she has helped expose others in the organization to environmental justice topics. Dr. Osborne Jelks is a recognized leader in urban environmental justice and environmental education and has been featured in People Magazine and The New York Times. In 2014, she was recognized by the White House as a Champion of Change.

Among career highlights, Dr. Osborne Jelks discusses seeing successful changes taking place in the communities in which she works. Despite challenges, she remains in the environmental field because she believes that if change is going to happen, it'll be up to her, stating that "this work is part of [her] calling... helping communities to empower themselves and be change agents" (2004). Dr. Osborne Jelks considers helping establish the West Atlanta Watershed Alliance to be one of her most significant accomplishments.