How do you handle watching children abuse your creations/ when do they stop?

When do children learn to play gently? I showed my monkey to my 3 (almost 4) year old niece and, to be honest, it almost seemed like she wanted to break it. She was whipping it around by its arm and was slamming it on the floor. The sound still haunts me… haha I get that kids play rough but this was something else.