I've started reading The Diaries of Isabelle Eberhardt (English translation by Nina de Voogd, edited and annotated by Elizabeth Kershaw). The original was written largely in French, with a few interludes in Arabic and Russian. Most of the text is written in the first person by Isabelle Eberhardt herself; however, there are some intervening paragraphs which seem more biographical, brief descriptions of what she did in some intervening period, and which are written in a different font in the online PDF. Here's an example that shows the contrast:
Written at El Oued, 17 September 1900, noon
Yes, there is indeed a tiny light on the other side of that Eternal Chasm.
Isabelle uses the small amount of money sent to her by Augustin to buy a horse and names him Souf, after the region. She derives great pleasure and solace in her lone rides across the sands, but financial difficulties owing to complications in her legal claim to her mother’s and Trophimowsky’s estates are beginning to take their toll.
Monday, 9 October 1900, 9 o’clock in the morning
Shortly after the maghreb last night, rode Souf by the back of the café through the white, sandy streets beside houses that are half in ruin.
The bright red sun had just set behind the dunes along the road to Touggourt. A few moments earlier, just as the sun had been about to disappear, I had spotted the silhouettes of two Arabs clothed in white standing on top of the little dune where the lime kiln is; they looked as if set against a heavenly light. The impression was a biblical one, and I suddenly felt as if transported back to the ancient days of primitive humanity, when the great light-giving bodies in the sky had been the object of veneration . . .
Clearly, these biographical notes are not part of the original diaries. Perhaps they were added later by an editor, to make certain elements of the story clear to readers who don't know details of Eberhardt's life. (For example, the horse Souf is first mentioned in the third-person note quoted above, and then mentioned without explanation in the following passage of the diary.)
What is the provenance of these notes? Who wrote and added them, and when? Were they originally in French and translated along with the diaries, or part of the English translation?