Her response: "I'm not being snotty, you are the one who has the attitude"
I am looking for all the advice I can get but do you think if I gave that response that it would just start an argument? and to me using the word "snotty" sounds juvenile and entices a negative response from her. it may also lead her to think a button had been pushed.
Try talking to her in an adult, negotiating way. "I think we have misunderstandings because of the way we talk to each other. I will try not to have an attitude with you, if you will try not to have an attitude with me. To help us recognize those times when we might misunderstand, let's just ask nicely if the other person is mad before we assume there is an attitude problem. After all, our lives will be better if we try to get along.'