I'm no expert but I wouldn't start forwarding incriminating emails to other staff just to get people in trouble, I'm sure no good can come from that. Like Spaghetti says you've let her know you're well-informed and watching her every move smile You probably just want to keep jollying her along now rather than get into a blame storm so I'd keep it reasonably light by saying something like you weren't aware after talking to teacher that writing the IDEP was underway but if that's the case please make sure you're involved.