Non-member of a Class Team receiving Invitations to Meetings

A teacher at our college has, over two semesters, been receiving emails notifying her of a meeting in another teacher's class (different department and faculty). She was never made a member of the team. Here name does not appear in the members list. But every time the owner of the team creates a meeting for her students, she receives an email notification and her calendar is blocked off and cannot seem to delete the meeting from her calendar.

What could be causing this situation? Since she is not a listed member of the team, we cannot fix the problem by removing her from its members list.

Thanks in advance.