First of all, please know that it common for mil and dil to have issues.
The reason for this is because the mil and dil are in very different stages of life.
The dil many times already has her friends, sibilings, mom… who she is close with and might not feel comfortable confiding in her mil who she might feel is very different from her.
The mils forget how it was for them when they got married so they are expecting things from their dils that they did not want their mils to expect from them.
The mils forget that to make a marriage work it takes a lot of hard work. They must give the dil privacy and space to enable their dils to focus on their husbands to build a good marriage.
Your wife is working ??(you did not give a lot of details) and also must adjust to the additional responsibilities bestowed on her when she got married. She probably just needs to focus on her relationship with you=her marriage and can’t take the effort to focus on her relationship with your mother also.
Why? because already by your post, I could tell that your mother is NOT showing the utmost care and concern for your wife (and she does not realize it (please dont think I am bashing your mother-I am just trying to explain from another point of view )). I could tell that your mother has expectations from your wife that might be unrealistic.
You mentioned you go to your parents for shabbos. So, your mother should feel good about that. She should focus on what your wife IS doing and not on what your wife is NOT doing.I know a dil who rarely goes to her mil for shabbos but always goes to her mother because she feels uncomfortable at her mils.
Another thing I noticed is that your mother is comparing your wife to her other dils. This is a big error. A good parent does not say “well, yoni is great in school and behaves well, but shoshana misbehaves, so I am insulted that shoshana misbehaves!” No, a good parent realizes that every child is different and ultimately shows care and concern for each child’s needs”
Your mother is a lovely person, and it is beautiful that she wants to have a close relationship with your wife. However, she must accept your wife for who she is and what she wants. She should never compare your wife with the other dils. I am assuming her other dils are married with kids(you did not give details), if they are, then conversation is easier because one could talk about her grandchildren.
Your wife might not feel comfortable at this stage talking to your mother. There are many good reasons for your wife to act this way.
Let me tell you that I am talking from experience. My mil has many dils and has trouble recognizing that my husband=her son, must put my needs first.
I am concerned that you only talk from your mother’s point of view, but I am glad that I could help realize your error. Now that you are married, you MUST SUPPORT YOUR WIFE’S NEEDS/DESIRES/VIEWS… AND DEFEND HER AT ALL TIMES. What this means is that you should have defended your wife when your mother told you how she felt and then you could have gone to your wife privately and discuss it.
First, DON’T TELL YOUR WIFE THAT YOUR MOTHER SPOKE ABOUT HER B/C IT IS RECHILUS. Your wife will just feel resentment towards your mother and feel insulted that YOU DID NOT DEFEND HER.