In addition to the numerous realizations in the field of housing, the most important architectural work of Prohirija Hadzi Kostova-Peshikj is the city library "Brakja Miladinovci". The city library is one of the numerous cultural buildings built during the post-earthquake reconstruction of the city of Skopje. The short but intensive period was aimed not only to compensate for the loss caused by the earthquake, but also to introduce a significant quantitative and qualitative advancement in many areas, including education and culture.

The city library was founded in November 1945, but until 1973 it operated in a minimal space that could neither meet the complex program requirements, nor the continuously growing book fund.

The new city library was built on a prominent location within the "Bunjakovec" settlement, along the "Partizanski Odredi" Blvd. and in the immediate vicinity of the Faculty of Architecture and Civil Engineering and the open market - "Bunjakovec". Although predominantly prismatic in its spatial figure, the compactness of the building is visually shattered by a series of rhythmic indentations and mass ejections. The white concrete façades are well proportioned, with a series of concrete elements used as railings and brise soleils, further enhancing the façade dynamics. The central hall is the main architectural theme in the interior of the building, zenithally lit and extending in its full height. Around this central element, following a clear functional scheme, the spaces for storage and the book fund are arranged, together with the reading spaces, administration and services.

For her architectural work Prohirija Hadzi-Kostova Peshikj received a special recognition at the "Beton" construction company in 1981 and a special recognition at the Biennial of Macedonian Architecture (BIMAS).