Mary, thank you for your offer to help. I will speak to my boss about it so in the meanwhile, please hold off talking to our manager.
Like the last poster, I assume that the "boss" and the "manager" are two different people. If not, then don't use two different words for them. Is the "manager" both your manager and Mary's manager. If so, then "our manager" is fine. If not, then it should be "your manager" or "my manager".
The reason I have added (about it) at the end is because I assume that you are not instructing Mary not to talk to the manager at all in the meantime, simply not to talk to him/her about this specific subject!