Thank you so much for all the wonderful suggestions!!! I really appreciate it.

jumping rope...these gums for it, I do not know the English word. But it is flat and light-weighed.

Scissors, pencils, biros, ruler, rubber, lighters/matches, a small raincape (these very thin things which do not last a lifetime, but I think she could easily put it over her coat when heavily raining, and it is small and light), animal postcards, a little calculator, childrens plasters, balloons, toothbrush and toothpaste, little calendar, little packages of eating gums, children´s watch, water ball (with the earth on it, so a "blow-up globe for playing") which you have to inflate with air, foldable lantern, little barby doll, dynamo torch, little sweet packages (gums), quartett game, puzzle, little stuffed animal (her favourite animal if possible)

That were things I have already sent to my children in packages not exeeding 1 pound (500 grams) and not over 4 cm hight (ca. 2-3 inches). I like to sent "practical" things more than dolls. And Franchesca wrote about her watch: I only put it off for bathing, and Eunice painted a picture with her and the inflatable globe in her hands, so they seem to like it.

 things for her hair.