^agreed. *nods*
I still think that her knowing only after the entire incident is over would be better. If she knows, she would start being a hindrance. Not that she is stupid. Think about it. What will happen if she knows about it? Will gosho turn her into a super detective that helps conan/ Shinichi to fight the BO? If ever she finds out about it, her role would change.
Also, if she found out about it, would she keep quiet and allow Shinichi to catch the BO himself? She might actually be proactive and gets herself into different trouble. I believe that is what Shinichi is trying to avoid. I don't think Shinichi feels that telling her would bring trouble to himself. Rather, he wanted to tell her. But to protect her, he can't.