Condo board member holds association ransom over loud A/C unit

We have a condo association board member who owns a unit on the top floor of the building. The A/C units for everyone's unit are on the roof. She is stating that our A/C unit is causing her to lose sleep when it is left on by our commercial tenant. (The building houses 14 residences and 4 commercial units).

We have requested that our very large unit be divided into 2 units and the condo board and the attorney suggested we divide into 1- commercial unit and 1 residential unit in order to help everyone out in the building since no one is able to refinance due to the Commerical vs. residential ratio. We agreed and have already paid the Attorney (6 months ago) to move forward. The Decision to do this has to be unanimous with the Building owners. The Board member with the A/C unit over her head said she won't agree until we move the unit off of the roof and until she is able to sleep nights without any noise in her unit. We have been to her unit and there is noise from all units not just ours but we have offered to move the unit to the outside wall but cannot guarantee total silence in her unit. She has stated she will hold back her vote until she has total silence which is preventing us from moving forward. (She had an issue with our daughter regarding the A/C unit 2 years ago and she threatened to throw a wrench into the unit to destroy it and our daughter filed a police report - of course this was prior to her being a board member) We think this is the reason for her holding back her vote. She has also threatened to impose fines of $100 per day until the noise stops from the A/C unit. Isn't she being unreasonable to say the very least? What are our rights when a Board Member "throws their weight around" to the detriment of a paying condo owner?