My bet is that the letters she is writing are her opinion. I am sure that they are broadly aligned with the mandate and strategy that the board has given her but she is not being directed to write anything nor is she having it approved first in my opinion.
and you would lose that bet. She is the spokesperson for a Governance Board and works at the direction of said Board. There is no way she would have written that letter without at minimum, direction from the Executive.
I was on that Board for 4 years, 2 of which on the Executive. I am in contact with several members of the current board...she can present ideas and suggestions/guidance as that is part of her mandate, but no way will a public statement in her capacity as Chamber CEO like the letter be issued without first passing it through the Executive if not the whole board