Three years later she obtained her master's degree on same University and since then, has worked as a self-employed cultural worker. In 2022 she obtained Phd in the field of painting.

Kastelec has exhibited in Slovenia and abroad, including Austria, Italy, Netherlands, France, Poland, Czechia, Germany and territory of Ex-Yugoslavia.

Her creative opus consists of painting, illustration, animation, and video. Since 2001, she has focused on the topic of food, specifically within the context of relations between the visual, memory, and taste. In her paintings, she illustrates the codependence of organisms and sustenance.

Moreover, she is exploring the multilayered meaning of objects, which she portrays in her paintings. She is particularly interested in the topics of thematisation, most prominently the influence and manipulation of science with plants and animals.