I am always happy to receive illustrations by Fiep Westendorp (tulips are a bonus!). But this time I was double happy to get also a postcard of Annie M. G. Schmidt, the author of Jip and Janneke stories (among many other that I have not read - yet). And with a matched stamp. I like having two different pictures of her.
The letter was sent by (had you guessed?) Heleen (the Netherlands).