Maybe you can show her some other toys that you really like, aren't hazardous, and work for you. Then delicately explain why think the ball may be hazardous? Maybe say you wanted one for your hens, and overly express how genius the idea is, and how cool it is, but maybe there other toys that may work better.
The hardest part is starting the conversation, so maybe starting with, "look at these super cool chicken toys I found" or something similar. She may even get more excited about the other toys, and care less about the ball after you chat.