She probably knows; she may well not be "in love" with you by now. Hopefully, though, you do Love her - over the period of 25 years you have grown to love her more deeply than the relatively short-lived stage of being madly in love. Such feelings are almost invariably temporary being so emotionally intense. Ok, so the passion and sexual desire have waned, and you probably yearn for that again - but with someone with a younger body. That happens with a lot of men, of course, but you need to work on what you really want for the future.