obsessive_a101 's post reminded me that some months ago I found a lot of great theatrical reviews on New York Times. It is amazing that you can find even the ones from 1978. I've made a list of almost all of Mary's performances, and a collection of these NYT reviews as well. I posted it
on my blog. The article itself is in Hungarian, but don't let this discourage you :). You have to scroll down about three paragraphs, and there you can find the list of plays, roles, theaters, and the reviews. Not all of the reviews are positives (especially the early ones), but at the end they give a pretty good picture about her development and maturing in terms of acting skills and talent. It is fascinating.