Marcy,
I am afraid your email slipped by me. I apolgize for the delay in responding. I do not belive your Great-Grandmother, Mary May was a daughter of Jacob H. Samuel Nace Daub (father to Jacob H.) had at least 6 sons that I know of. So would be possible that she would be a daughter to one of them. I will be glad to see if I can find any information for you.
Jane