Born in Tanzania as a refugee, she was educated at the Institute of Development Management in Mzumbe and then worked for eight years at the National Bank of Commerce in Dar es Salaam.

[2][5] Gasinzigwa and her family returned to Rwanda in 1994, after the Rwandan Patriotic Front, led by Paul Kagame, won the civil war and established a new government.

After seven years, she transferred in 2001 to the Ministry of Environment to work with the United Nations Development Programme on a resettlement effort for people displaced by the war and genocide.

[9] The commission was tasked with evaluating and proposing reforms to state structures which had in the past led to divisions and conflicts as a basis for charting a peaceful path for the future.

[9] The ministry was designed to address gender issues in government policy and legislation and to serve as an interface between women's organisations and their international donors.

Speaking with lawmakers, she stressed the need to adopt policies and laws to provide adequate health care and eliminate marginalisation and stigmatisation of those with disabilities.

She outlined the steps Rwanda had taken to meet the Beijing action targets, explaining that the country's approach was to allocate financing for gender equality programmes in the national budgeting plan to avoid having insufficient resources for achieving the goals.

[21] Gasinzigwa was elected to serve as a member of parliament in the East African Legislative Assembly (EALA) in 2016,[22] to complete the unfinished five-year term of Christophe Bazivamo.

[23] The EALA is a regional legislative body that works to integrate the socio-politico-economic policies of its member nations,[22] which include Burundi, Kenya, Rwanda, Tanzania, Uganda, and South Sudan.

When Susan Nakawuki, Uganda's MP, introduced a resolution in 2018 to establish the independence of the legislative body from the East African Cabinet, Gasinzigwa seconded the measure.

[32] As a part of the peace and security strategy, she urged other legislators to adopt the measures recommended by Fatuma Ndangiza, chair of the EALA Committee on Regional Affairs and Conflict Resolution, to prevent genocide.

[33] According to Ndangiza, the key to making strides in that area was to address budgeting and staffing shortages in the East African Community's Peace and Security Department.