While I'm away, readers give the advice.
My mother-in-law was used to being the most important woman in her son's life. And I had taken that position from her. And her only defense was to find fault in an effort to strengthen her position.
My best defense has been to pay attention to what is important to her, and focus on that - and find ways to include her that she is comfortable with. The barbs still come, but have become less frequent over the years. Our now-grown children have a great relationship with her, having learned that sometimes the most challenging personalities you learn to deal with in life are found in the people closest to you.
Years ago I was an elementary school principal. Each year, at an October staff meeting, I would say (to groans from my longtime staff), "Here's what I want you to do this week. Take some extra time and work with the one or two children in your class who irritate or put you off. Figure out how you can best 'reach' them."
I suggest that parents ask themselves what they could do to "reach" their fussy children. Some (not all) of my staff would tell me, "You know, once you try, it isn't so hard to like those kids."
Many years ago, our wonderful pediatrician told us that children go through periods of equilibrium and disequilibrium, lasting anywhere from hours to several months or more.
As we have raised our three children, these words have rung true over and over again. My wife and I would often remark that "Child X is really in a good way at the moment." A period of equilibrium. Or "Child X has been totally out of sorts over the past couple of weeks" - a period of disequilibrium. Viewed through this lens, we came to appreciate the maturing process with greater patience and understanding.