Martha (Polly) McLachlan died on November 25, 2008. A complete obituary can be found in the Stillwater Newspress archives.
http://www.stillwater-newspress.com/obituaries/local_story_333144910.html

Polly McLachlan was the wife of former faculty member E.K. McLachlan. Professor McLachlan advised many graduate students and a fellowship  named for him is presented each year. For many years after the death of Professor McLachlan, Polly attended the annual awards ceremony and helped with the presentation of the McLachlan award.