Kathryn was appointed a civil service commissioner in April 2012 and acted as the interim First Civil Service Commissioner from April to September 2016.
Cafodd Kathryn ei phenodi yn Gomisiynydd y Gwasanaeth Sifil ym mis Ebrill 2012 a bu’n gweithio fel Prif Gomisiynydd y Gwasanaeth Sifil Dros Dro o fis Ebrill i Medi 2016.