Ignore her in terms of project management. At the same time be very polite and friendly in terms of personal relations.
At the same time be very strict and explicit with your project members. They have to understand who is giving orders - the project. Sooner or later they will start ignoring her and obeying project rules.
This may help: http://www.yegor256.com/2015/01/26/happy-boss-false-objective.html