After completing her graduate studies, McKenzie took up residence in Oxford, becoming the Rhys-Davids Junior Research Fellow in 1987. She held this position until 1990, when she became a
British Academy Post-doctoral Research Fellow. Between 2000 and 2002, McKenzie was on the committee of the
Palestine Exploration Fund. She was a Queen Elizabeth Fellow at the
University of Sydney and a Fellow in Historical Studies at the
Institute for Advanced Study in
Princeton, New Jersey for the 2003–2004 academic year. McKenzie's 2007 book
The Architecture Of Alexandria And Egypt was awarded the James R. Wiseman book award by the
Archaeological Institute of America in 2010, which described the monograph as a "a monumental accomplishment". McKenzie's work had been instrumental in understanding how ancient architecture influences later buildings, particularly the influence of the
Pharos, the lighthouse of Alexandria. McKenzie worked on the
Garima Gospels, publishing a volume on them with
Francis Watson in 2016. The book is the first to reproduce all the illuminated pages in colour. McKenzie also curated an exhibition on the gospels,
The Hidden Gospels of Abba Garima, Treasures of the Ethiopian Highland, at the Ioannou Centre, Oxford in 2017. In 2016, she received a
European Research Council Advanced Grant for the project
Monumental Art of the Christian and Early Islamic East: Cultural Identities and Classical Heritage. McKenzie died on 27 May 2019 at the age of 61. == Selected publications ==