The translation is by Tinke Davids. The Afterword of the Memoirs was originally written in German by Annegret Nippa in 1885. However anyone interested in the background to the memoirs can much better read ref 1 "An Arabian princess between Two worlds" by van Donzel.
Anyone interested in the bibliography of the Memoirs should read ref 3 "Het leven van Salme (1844-1924) prinses van Oman en Zanzibar, en de vroege uitgaven van haar memoires" by Hielke van der Wijk