The career? Yes, potentially. Although as a fairly high-profile reporter (within the industry in which she works, at least), I would be curious what her career earnings are thus far (which is very different than what she has saved, of course). And, given that (somewhat) high-profile, such an affair might not be a career-killing deathknell (as you yourself mentioned in another post).
Her marriage? If you're cheating on your marriage at the age of 40+, I'd tend to think you really don't value that marriage, in which case not much has been lost. Or, she has the emotional intelligence/maturity of an adolescent/young adult insofar as her inability to consider the longterm outcome of her choices and how those will impact her future life and happiness.
Of course, impulsive decisions leading to cheating/affairs are not always (or rarely, even) thought through in a deliberate, careful manner, so perhaps attempting to analyze the behavior as if it was, is approaching the topic from a fundamentally flawed perspective.
At the risk of making this about myself, I actually had a recent encounter that made me think about cheating a bit more. I'm 31, never been married, had a handful of hookups throughout undergrad, but only seriously dated two people for an extended period of time (3-4+ months) during my life. My current girlfriend is the polar opposite of my previous. First girl I dated was sociopolitically conservative (which was the cause of a lot of tension and ultimately the end of our relationship), but incredibly gentle, kind, easygoing. My current girlfriend and I are politically aligned, but she's a radically different person: feisty, high-strung, at times intense/loud, but also very independent and highly driven - she also has a child from a previous relationship, so the experience of becoming a dad to her son has been truly special, but that's neither here nor there.
At any rate, back to the cheating stuff, I've seen the woman who cuts my hair on several occasions. The first time I ever saw her, I completely accidentally bumped her butt with my hand as I was sitting down in the chair and she seemed to notice. Following that appointment, she texted me from her cell # recommending certain product for my hair, which I took as a rather personal gesture and made me wonder if she thought the butt-touch was a deliberate attempt to show interest. She is young, attractive, and I'd absolutely be interested in her if I was single, but again, it was an accidental bump. Many months go by, this hairdresser leaves her previous studio and I can't find her to book an appt, so I get my hair cut elsewhere and then let it grow quite long.
Recently, I managed to track her down, and she's now running her own independent operation out of a private studio. I booked an appointment and when I show up, she is talkative, bouncy, excited to see me. As she's cutting my hair, she's leaning forward such that her breasts are pressing against the back of my head/neck. It was both pleasurable and exciting - I hadn't felt a spark like that in a long, long time. In that moment, it totally clicked in my mind how people could find themselves in such situations and impulsively go for it, for lack of a better term. People don't cheat because of some well-deliberated, carefully thought-out calculus - it's because it's exciting and spontaneous, and that very much explains why people will (sometimes) cheat with individuals considerably less attractive than their current partner - it's about the novelty and spark.
Nothing happened between the two of us - she finished my haircut and we moved along. And with some time to reflect on that encounter and my current relationship, I am very glad I did not pursue anything further.