1. She never stops comparing
One of the first signs that a mother-in-law is jealous is that she never stops comparing the past with the present, no matter how hard you try to be different and make changes along the way. She will never be satisfied, and she will always try to diminish everything you do by saying the other person did it better. This attitude denotes the fact that the mother is actually feeling insecure and it just manifests this way as a result.
In most cases, the true root of the issue is the fact that she believes she now comes second in her son’s life and fears that she could be replaced forever. And she will keep making these comparisons, and maybe you will eventually break up with her son because you can’t handle these criticisms anymore.