Hi Patricia, since this is an older post not sure if you got your answer yet to knowing Margaret's death date. I found her death record. She died on Aug 9, 1895 in Salem, Massachussets. My husband is also a descendent of John A Townsend and Johanna McCarty.
Here is my source:https://familysearch.org/pal:/MM9.1.1/NWH8-3HV