I found a solution but it will cost me $34.95. It is called TextExpander for Mac.
I tried the text substitutions and Chrome Extentions but they had limited success, they worked and then didn't. The TextExpander program works great but I do not want to spend the money but I may if I do this often enough.
So Anne,
While I am typing the letter and my grandmother writes," ...my great grandfather was President of the United States." I would type:
...my [[grandpa-xxx|great grandfather]] was president of the United States.<ref> grandpa-xxx was not president of the United States but he was president of the United Stump Removal Coalition</ref>.
Then my comments will show up as references at the bottom of the section. And Yes, I did set up a Free Space to enter the letter.
I have a lot of statements that need corrections or comments to be included with them so the text exanding saves me a few keystrokes.
I can type ,r and get <ref> and I can type ,e and get </ref>. I know it is only a few keystrokes but I have a lot of them and I do not have to use the Shift key to get <. Which is a bit akward for me.
UPDATE: I found aText, an Apple App for $5. I bought that and so far it works perfect.