Kamanga was born in 1970. She entered private practice after she graduated in law from the
University of Malawi in 1995 and two years later took a master's degree in the US at
Rutgers University in Women Studies. She obtained her masters (LLM) degree from
Cape Town University. She was appointed as Registrar in 2008 and she served until 2012. She became a High Court Judge in 2013. She was appointed with three other judges by President
Joyce Banda. Kamanga was involved in a case about
prostitution in Malawi. Eleven sex workers were arrested in 2009 in the southern city of
Mwanza. They were taken to a hospital and forcibly given HIV tests. The positive results of the tests were later read out in open court. The sex workers later sued the Malawi government for "damages as compensation for violation of their constitutional rights and trauma suffered as a result of actions of the police and a hospital”. Kamanga ruled that the sex workers should be compensated, and that the actions of the police and health workers were "irrational, unjust, unfair and unreasonable." Kamanga became a Malawian supreme court judge in 2022. In June 2022 she sentenced five men to life imprisonment with hard labour for planning and then murdering an albino man in 2018. The five included the man's brother, a member of the Catholic priesthood, a member of the police and a medical worker.
People attacking albinos is not an unusual crime in southern Africa and in this case they had extracted human tissue. The government particularly support punishing people associated with crimes against people with albinism. ==Private life==