I have a copy of a newspaper obit of your grandmother's in Quanah, TX. Says Mrs. May C McMennamy was born June 21, 1888 in Missouri. Contact me directly and I'll try to scan it and send you a copy if you want it. I came by it from one of my Aunts in Wichita Falls. I had no idea who she was until one of her sons called me. I told him about it and I was shocked to find she was his mother. Turns out we're cousins.
I also have info that goes back to John McMenamy, b: June 17, 1738 in Northern Ireland.