If I were on your committee, I would advocate a decision of the committee, all duly minuted etc, to write a formal letter to this owner from the executive committee stating:
-examples of instances when it appears that the owner has misrepresented herself as a representative of the committee.
-that it is a function of the committee to represent the interests of and exercise the functions of the owners corporation.
-that maintaining good relations with potential suppliers of goods and services to the OC is an important function of the committee.
-that the committee requests that she desists from representing herself as being a committee member or giving that impression to potential suppliers of goods and services.
-that she explicitly makes it clear that she is not a committee member and is enquiring in a private capacity if she does talk to potential suppliers of goods and services.
-that the committee appreciates her experience and enthusiasm for proposals for the improvement of the property but would prefer that she bring her ideas for discussion with the committee before being advanced too far.
-that if the owner persists, the committee will seek an order from the Tribunal that the owner desists from representing herself falsely as a representative of the committee to the detriment of the OC’s interests.
I suggest that a copy of the committee’s letter be also sent to the managing agent.
You have my sympathy. I have been in a similar situation as a committee member. An owner who had previously been a committee member sought to ambush the committee at an AGM with quotes for certain expensive (but unnecessary) maintenance as part of her effort to dissuade owners from agreeing to spend money on an unrelated proposal. i.e. Panic people into thinking we needed to urgently spend lots of money on one thing so there would be no money left to spend on the other thing. By chance I contacted the same supplier who was surprised I did not already have his quote. He then sent it to me directly and it became clear that the owner was also doing some selective quoting of that supplier’s advice. Almost a decade later the thing she wanted us to spend lots of money on has still not been done, still does not yet need to be done, and our sinking fund has ample provision for it when it eventually does need to be done.