canine:
It happens to be the case. There is no correlation between the husband not wearing jean pants and the wife not wearing jean skirts.
The reason is that there are reasons for men to not wear jeans, but there is no reason for women not to, and only women who are all into feminism don’t wear them. (or girls who have been told by the teachers who are into feminism that it is assur.)
And if you don’t believe me that there is feminism going on in these joints, just ask yourself why your daughter came home from seminary davening maariv and thinking she has a chiyuv to learn torah)