The meaning of the idiom it is a lady’s privilege to change her mind is the toleration of a changed or reversed decision when done by a woman more readily than when done by a man.
1. We expected the manager to be angry with Nancy when she informed him of her inability to join with us for the appraisal meeting at the last moment. To our surprise, the manager was calm. We decided that it must be the case of a lady’s privilege to change her mind.