The diary reflects the life of a young girl whose horizons were limited by social and religious constraints. She was eager for self-improvement and created for herself a series of routines and good intentions, which are inserted into the end of the diary. In the daily entries she often refers to these programmes by a system of capital letters and Roman numerals.

The collection consists primarily of letters from Ruth Darwin to members of her family but predominantly to her sister (Emma) Nora Darwin, and correspondence and papers arising out of Ruth's work with the British Committee of the French Red Cross in France in 1917-1919.