I did a little bit of research but couldn't tell if Margaret L. Wendt was related to the Wendt Dairy people. Here is a little excerpt with photo about her from Western NY Heritage magazine:
Western New York Heritage Magazine
Margaret L. Wendt, whose namesake charitable foundation has ignited a new era of philanthropic outreach in Western New York, would be surprised indeed a the fame she now has attained. Her father would be astounded.
Forbidden to attend college and discouraged from following the footsteps of a "progressive" cousin in the early year of the last century, Miss Wendt lived a quiet life that tempered the privilege of her class and station with a personal commitment to charity - a commitment that evolved, eventually, into a multi-million-dollar fund that was among the first in this area to seek out projects with great potential impacts on the well-being of the entire community, rather than simply respond to pleas for assistance.
To read more of Mike Vogel's story, see page 9 of the Spring 2002 Heritage Magazine.
Western New York Heritage Press, Incl