Amongst the wreckage and aftermath of an affair, there are many processes that many women like yourself go through before they are able to reach a place of healing.
One of these processes is an unfortunate phase of uncertainty and dangerously low self-esteem.
During this phase, many women begin to compare themselves to the other woman. They think about the other woman almost as much, if not more, than their adulterous husband.
Is she prettier than me? Was she better in bed? Did she make him happier than I do? Is she thinner/taller/fitter/sexier than I am?