While in exile, Ngwevela procured a Diploma in Political Science at the Pushkin International Institute in Moscow in October 1980. From September 1986 to August 1988, she managed to acquire a Post Graduate Diploma in Administrative Studies as well as a Masters Degree in Public Administration at the University of Liverpool, England. She also attended courses on International Relations at the Institute of International Relations, Potsdam, East Germany (former GDR) from January to June 1989.
Ngwevela served in diverse capacities as member of the African National Congress (ANC) in exile. She was based in Zambia, working in the ANC Department of International Affairs, on the North American and European Desks. She also worked as the Administrative Secretary of the ANC Women Executive Committee. This post demanded her to consolidate contacts and liaise with Women’s Groups in South Africa and the global Anti-Apartheid movement. Her responsibilities extended to representing ANC Women’s issues at international forums and conferences at the UN, OAU sub-regional meetings, the Non-Aligned Movement and the Pan African Women’s Organisation, to name a few. She also served as Information Officer at the Luanda office of the Information Bureau of the Pan African Women's Organisation in Angola.
On her return from exile, Ngwevela worked on two projects between 1991-1994. She worked as Community Development Advisor in Community and Urban Services Support (CUSSP), a USAID funded project dealing with housing and urban development and as Project Coordinator at UMZAMO Development Project, a Cape Town-based hostel-to-housing development project. Regarding the latter project, Ngwevela was assigned to plan and raise funds to upgrade and convert former migrant labour hostels into suitable accommodation.
- Ngwevela worked for the Department of Local and Provincial Government as the Coordinator for the Local Government Transition Policy Project, whose primary responsibility was to facilitate verbal engagements between statutory and non-statutory institutions during the initial phase of the transition in 1994 under the Local Government Transition Act. In 1995, Ngwevela joined the Department of Foreign Affairs as a Director in the Office of the Minister of Foreign Affairs. She was private secretary to Alfred Nzo, then minister of the department. Ngwevela travelled extensively while in exile and also as secretary to the minister. She visited countries in Africa, Europe, Australia, Cuba, Canada and Asia. In 1998 she was appointed to head the Foreign Service Institute (FSI), the training academy for the department's diplomatic corps. On 1 February 1999, Ngwevela was appointed SA Consul General to New York. At the time of her departure from Pretoria, she was serving as the Secretary of the South African International Diplomatic Association. She held the following positions:
- Co-founder and member of the National Housing Forum in the Western Cape,
- Member/advisor of the Cape Metropolitan Forum Steering Committee,
- Member of the (Local Government) Finance and Services Working Group,
- Technical advisor to the Head of the then ANC Local and Regional Government and Housing Department.
Ngwevela has two children.