One of the reasons that the fairer sex coined the word “Ms.” during the Women’s Liberation Movement was because they didn’t want men to know whether they were married or not. The argument was that when a man puts “Mr.” before his name, nobody really knows whether he is married or not. A bachelor is a “Mr”, and so is a married man. Whereas ladies had two different titles; an unmarried woman was referred to as a “Miss.”, and a married one was called “Mrs.” So in the early 70s women came up with a title which wouldn’t provide any information about their marital status. That word was “Ms”. So the answer to the question is that it’s all right to address a married woman as “Ms.” The word is pronounced like the word “Miss” except that the “ss” is pronounced like the “z” in “zip” and “zoo”.