Yes, there is a cemetery at St-Edouard-de-Lotbiniere. It dates back to 1863. Do you think that your great grandmother is buried there? Her name should be in the Drouin Collection data base available on the ancestry.ca website. I live at St-Edouard-de-Lotbiniere and could gladly have a look and see if a tombstone still exists in our cemetery. Not all lots had a tombstone though, many had only wooden crosses that have disappeared with time. Just let me know how I can help you and I'll be glad to assist you in your research.