In South Africa's
first post-apartheid elections in 1994, Mashego-Dlamini was elected to represent the ANC in the
Mpumalanga Provincial Legislature, where she served for the next two decades. She also served in the
Executive Council of Mpumalanga during that time, initially as
Member of the Executive Council (MEC) for Health, Welfare and Gender Affairs under Premier
Mathews Phosa and then as MEC for Agriculture, Conservation and Environment under Premier
Ndaweni Mahlangu. She remained in her ANC Women's League office during this period, and, between 1999 and 2002, Her co-option followed the ANC's
50th National Conference in 1997, at which the Mpumalanga ANC had unsuccessfully attempted to secure her direct election onto the committee. She was also viewed as a possible "dark-horse" contender to succeed Mahlangu as ANC
provincial chairperson in 2002, though that position ultimately went to
Fish Mahlalela. Under Premier
Thabang Makwetla, who governed Mpumalanga from 2004 to 2009, Mashego-Dlamini held two portfolios: she was appointed as MEC for Public Works in 2004, but she became MEC for Local Government and Housing in a reshuffle in 2007.'''''' While she was serving in the latter office, in August 2008, she stood for election as deputy
provincial chairperson of the ANC's Mpumalanga branch, but she was defeated by Charles Makola; Makola's candidacy was backed by
David Mabuza, who became provincial chairperson at the same elective conference. Unlike Mabuza, Mashego-Dlamini was a supporter of Premier Makwetla and of former ANC president
Thabo Mbeki. Mabuza became
Premier of Mpumalanga after the
2009 general election, and Mashego-Dlamini, still perceived as a political threat to him, was not initially appointed to his Executive Council. However, she joined in November 2010, when Mabuza appointed her as MEC for Agriculture, Rural Development and Land Administration. In another reshuffle in July 2013, she became MEC for Health and Social Development, a portfolio which she held until the
2014 general election. == National government ==