Hello! I work as a designer periodical printing. I am the mother of a little girl Varvara, she will be glad to receive a postcard with a picture of a dog, a cat, a hedgehog... She loves animals :)
As well I'll be pleased to get handwritten postcards; take down some words in your native language with translation and/or transcription. You can write on the postcard what is the temperature outside or is it snowing/sunny/raining... Don't bother with an envelope, the travel scars just add character!