After brief tenures with several companies in the 2000s, including a position as head of human resources at a hospital, Makwinja became acting CEO of the Botswana Investment and Trade Centre in 2012.

Though the initial vote-tally in the primary showed her losing to incumbent Vincent Seretse by just 45 votes, Makwinja called for a recount, claiming there were "irregularities" with the election.

She has faced several challenges during her tenure, including an outbreak of "mass hysteria" at a school in Salajwe in 2019,[9] a textbook shortage in 2021,[10] and the reformation of the country's curricula.

In 2022, she was a speaker at a conference organized by the United Nations Population Fund and the Southern African Development Community on improving sexual and reproductive health and rights.

[18][19] On 9 September 4 2024, Makwinja was appointed Minister of Environment and Tourism by President Mokgweetsi Masisi, and served in the role until the end of her parliamentary term on 1 November 2024.