On 20th September 2016, she was appointed Deputy Mayor of Warsaw. She graduated in administration from the University of Warsaw and earned her MA degree in EMBA (Executive Master of Business Administration) at the University of Management in Warsaw; she also completed postgraduate programmes in European Union studies at the Warsaw School of Economics and in EU Structural Funds at the Faculty of Law of Cardinal Stefan Wyszyński University in Warsaw. She is the co-author of the Act on the Structure of the City of Warsaw for the Agency for Municipal Development.

Mrs Kaznowska has been involved in the local-government administration of Warsaw since 1994.
Between 2003-2015, she held the position of Director of the Public Land Authority, a municipal budgetary unit responsible for the management of public space in the Warsaw city centre, the Śródmieście District, comprising over 300 hectares of parks, squares, roads, along with an area included in the UNESCO World Heritage List.

She is responsible for numerous city investments, including road and lighting modernisation, park and square revitalisation, and the construction of monuments and national memorial sites. Winner of several awards and distinctions in a nationwide competition for the best-lit municipality in Poland.

For the illumination of the walls of the Old Town in Warsaw, included in the UNESCO World Heritage List, Mrs Kaznowska received the prestigious international Jean Poul - L.Allier Prize for Heritage from the UNESCO Chapter.

Awarded the Bronze Cross of Merit by the President of the Republic of Poland, the Silver Medal "Merit for the Engineering Forces" of the Polish Army, and the Honorary Gold Badge of Merit of the Society of Friends of Warsaw for her social work and other services to the city.

In the years 2015 – 2016, she was the Chairperson of the Palace and Culture LLC Board.

As the Deputy Mayor of Warsaw she performs duties of the Mayor of Warsaw in the field of roads and public transport; she supervises the work of the Municipal Road Authority, the Public Transport Authority (Metro, MZA, SKM), the Road Renovation and Maintenance Company and the City Cleaning Authority. As the Deputy Mayor of Warsaw, she is also responsible for coordination of road investment and maintenance, infrastructure, along with sports and leisure in the City of Warsaw including the Capital Sport Centre (SCS) Active Warsaw, the Powsin Culture Park and 17 Sport and Leisure Centers.