text: "Ms. Chittister"? 
  Your message appeared among the three I was asked to rate as I was posting a message.  I lingered a little longer than usual before I rated it as 'Civil', but having done so, I looked for your post so that I could respond to it.
  Sr. Joan has been a Benedictine nun for over fifty years.  There's nothing inherently wrong or disrespectful in the honorific, "Ms."  However, the disrespect would be in the intention of the writer.  A deliberate attempt to disrespect Sr. Joan by referring to her as "Ms." succeeds: it's disrespectful, to say nothing of sophomoric.  Sr. Joan is well known in Catholic circles and beyond, and she is identified as a Benedictine sister at the end of the article.  But maybe you didn't know or notice.