Complex sentence: Waterhouse was appointed Librarian of the British School at Athens (1946-1947) and later, back in England was Assistant Lecturer in Classics at the University of Manchester (1948-1949).
Split into simpler sentences: Waterhouse was appointed Librarian of the British School at Athens (1946-1947). She returned to England in 1948 and worked as Assistant Lecturer in Classics at the University of Manchester (1948-1949).