I work for a bank.
Sitting on the board of a political commitee or holding public office even is ok for employees, and officers of the bank as long as it is cleared with the internal ethics people first.
Secondly she would be required to ensure that direct conflict of interest against the bank does not happen by recusing herself of any responsibilities thst directly involve the bank. She was treasurer of a super PAC, so if the PAC did banking with her employer then she would be in violation, otherwise she would be fine.
Assuming her Super PAC did banking with Lakeview or if she didnt go through proper channels to be cleared then I would agree with you but we dont know that.