People change. Some change is rapid while much is more gradual, but we all change throughout our lives. Women usually change more than men for a couple reasons. Children affect women more than they affect men, leading to bigger changes. Additionally, women go through various hormonal stages, and these result in changes in how they feel and think. (None of this is their imagination; there are actual changes in their brains and biochemistry.)
It’s a given your wife is changing. The question then is how well are you doing at keeping current with her changes? It would be nice if she sent you a regular memo with the changes going on, but even if she were willing to do that she probably isn’t aware of all the things changing.
Make a point of looking for changes. Become a student of your wife so you see the changes in progress. Ask her what is happening in her life (ask, don’t complain or accuse) and refer to the changes you see if she does not. Then make modifications to benefit both of you.