I agree with RobinD. Check your by-laws. At our school, only parents or guardians who have students enrolled in the school are considered members of our PTO.
I guess the first and obvious question is, what do your by-laws say about who can be potential members? What has she said is her agenda? I could probably better give suggestions if I knew what her agenda was, and specifically how she is impeding the group. tell us more
We have recently run into a difficult situation. A person has joined our PTO who is NOT a parent of a child served by our group (K-8). She has admitted to having a personal agenda to being a member. So far all she has done is to stir up arguments and impede the progress of the group. Any suggestions?