Thea obtained a BA(Ed) Fine Arts degree in 1989 and the BA Honours (Art History) in 1992 from the University of Pretoria (UP). After her studies she lived in Germany. Upon her return in 1991 she founded an art department at St Albans College, Pretoria. In 1993 she joined Frieda van Schalkwyk Art Consulting, founded by her mother. She has curated more than 200 exhibitions.
Thea established her own consultancy in 2005, focusing on managing private, corporate and educational art projects and programmes. Her work involves sourcing art for clients both locally and abroad, consolidating collections (also as part of business rescue) and valuations of collections and deceased estates. Her own artworks are stories of imaginary moments, images and objects in creation – in a sense a form of visual meditation.