Is a fear of your husband running off with a younger woman common among middle-aged, married women?

Or is my wife just being dramatic and paranoid?

We've been together for over 25 years. There's never been any hint of infidelity in our relationship. But, several times in the last few months, she's said things like, "thank you for not trading me in for a younger model," or "I get nervous, since you work with a lot of younger women, that you'll get tired of me eventually."

Is that a common fear among middle-aged, married women?

This is despite the fact that our relationship is stronger how than it has ever been, and it has been strong the entire time. It's just stronger now (went from great to even better) because our kids are older and less needy, so we get more time together, and we've reached a level of financial affluence where we can actually do fun things together, like traveling.