Hi everyone, just wanted to post an update. In August 2013 I visited my grandmother's hometown again to try to locate the paper trail that was associated with her being sent to St. Michael's. While I spent hours looking at family court indexes and such finally someone suggested I check the criminal records. I did, and found the entire file related to my grandmother's being sent to St. Michael's. So -- my point is, check everything because the records you seek might literally be right under your nose.
Good luck to you all!!