I had a lot of projects going on last year and never made it to Montreal until just this past February. I was focusing on other things and never thought to sort out the parents of Marie Louise Letourneau.
However I did photocopy the marriage contract of Albert Perot & Marie Louise Letourneau. I haven't had it translated yet, perhaps there is info in it that would shed some light on who her parents are.
I got a scanner not too long ago, but I haved hooked it up yet. I'll do that soon and scan the document into my PC. If I remember correctly, it was 2 or 3 pages. When I do, I'll e-mail you a copy.