Received from Heleen (The Netherlands). Re-sent to Paquita (PC).
It says, in Dutch: "Do you join the travel?". It is a postcard from the exhibition "Alexine Tinne. Afrikaanse avonturen van een Haagse dame" (='African adventures of a lady from The Hague'). It seems that this courageous lady (1835-1869) was the first European woman to attempt to cross de Sahara (but it ended tragically).
Update: I received later the stamp featuring Mrs Tinne