How do I identify and manage unknown location tracking on a child's Apple Watch?

My pre-teen received a message on her watch that says "Your current location can be seen by the owner of this item. For additional information, continue in FindMy on your iphone." It does not say what the item was, and we don't see any information about it in FindMy. What should be do to ensure her safety?

[Re-Titled by Moderator]