I agree with Guinevere, it does sound like an overreaction, but I'm assuming this happens w/your W frequently. Is she bitter and angry a lot of the time? These are usually signs that your W is harboring a grudge or resentment for you possibly based on past mistakes/lovebusters. And if she hasn't considered forgiving you, then it is time she ought to, not only for you and your M, but for herself.
I am dealing with Forgiveness now, myself, w/H (in the area of forgiving him for being dishonest in the area of finances, among other things...you can read details in my post under "prayer requests"). Only recently found out what Forgiveness really is. Here is the definition I got from "Women's Bodies, Women's Wisdom" by Christiane Northrup, M.D. (there is an entire chapter on Forgiveness...I recommend, as a gift to your W that you purchase this book for her...really...I believe every woman should have a copy of this book):
"Forgiveness doesn't mean that what happened to us was okay. It simply means that we are no longer willing to allow that experience to adversely affect our lives. Forgiveness is something we do, ultimately, for ourselves."
Do you have any idea what you may have done in the past (repeatedly?) that she finds so irksome and "rude"...or does it relate to any past wrongs on your part? Have you asked her to forgive you for those bigger things that you may have unintentionally done in the past? Then you may want to do that. But she must also forgive you. Granted, it must be on her own timetable, but it would be to her advantage to evaluate the basis for the resentment, rebuke it and forgive you....for the bitterness and anger will not help her healthwise, it will rub off on your children and will negatively affect other relationships in her life. As it says above, right now she is letting all kinds of little things (probably based on a bigger past grievance she holds against you) negatively affect her life and your marriage relationship.
Yes, you're going to have to find out what the deeper problems are, as you say...do the EN questionnaire at this site if you haven't already. Find out what's really eating her and causing this resentment. But until you guys both know what it is, it may be difficult for her to move to forgive.
God bless,
Suzy