Responding to several of your replies:
I have talked to her outside of Mass many, many times. She usually says that she will try, but acts very offended that I request this of her. Then, when she starts talking, which happens 100% of the time, sometimes I say “Shh,” politely. This usually works for a minute or so but she invariably will have something to say later. She will often comment on the poor singing of the choir (which really sets me off), but usually it is just non-essential stuff that could easily wait until after Mass.
I have not asked her what she suggests I do, but I will try this–put the ball in her court.
While I agree that sometimes something needs to be said to a child, most of the time a simple “Shh,” will suffice. At most a whispered “No” accompanied by a stern look will work. My philosophy is that if it is not absolutely essential that the information be conveyed by speaking, then it should not be done. Without children, there is nothing I can think of that would warrant any communication, other than “Help me, I’m dying!”
But this is beside the point. She talks just as much when we are by ourselves.
I think I would have the conversation about Mass again. But in a wider context, which is that obviously, you two have different ideas of what it means to be at Mass and what is actually happening on the altar, during the Liturgy of the Word, etc. She may feel more of a spectator and not see a problem critiquing the “performance.” That is what my DH does, in addition to adding sometimes really funny observations that he whispers to me and which I then have to suppress my laughter at. (He does not worship at Mass although he pretends for our sons.) I have a much more reverent experience if he is not there. Don’t even get me started about his father - you’d think he was a child of 4 and not a grown man - he whispers incessantly, draws on the bulletin, etc. and is a very bad influence on his grandson.
It troubles me that your wife is offended when you ask her not to talk. A request like that from one’s spouse should not be met with scoffing or offense when none is meant. When you talk to her, be very kind, but keep playing the broken record until she has to acknowledge your statement.
You: “I would really appreciate it if you would not talk to me during Mass. It disturbs my worship and puts the focus on your comments. I am praying and find it hard to concentrate when I am interrupted.”
Her: “I don’t know why my comments bother you! I am just saying one or two things to you, it’s not that much.”
You: “No, but really, I would appreciate it so much if you would not talk during Mass. I can’t concentrate on my prayers when you talk.”
Her: “I just don’t understand! I want to tell you something and I don’t want to wait until after Mass!”
You: “I understand that you want to communicate, but I’m asking you to wait until after Mass to do so. I just need you to stop talking to me during Mass. Can we try it this Sunday please?”
Eventually, if you say it with kindness each time, not losing your temper at her, she should surrender.
But you can also ask her what she can suggest, and you can suggest things too, such as - maybe if she writes her observations down on a notepad, you can promise to listen to each of them after Mass.
Don’t do it, but maybe it will give you a 
.
