I disagree that this is what is happening in this story. Just because she's considered herself straight her whole life doesn't mean she can't discover she's not now. And if a hot coworker confessing to her is what it takes for her to go "hey, maybe I do actually like women too" then so what? Everyone's journey is different. Some people just can't imagine how they'd feel about something until they are actually in that situation.
I remember hearing a story about this actually happening to a 40-year-old woman.
It's nowhere near as big of a shift as realizing you're gay, but something similar happened to me. I realized, years after having met a person, that I had a crush on them since we first met. It was just after hearing they had broken up with their long-time partner. I realized it, and then realized I had been subconsciously avoiding thinking about it until that moment.
Yeah I know of multiple women who have been married and had kids with a man only to later in life, after divorcing said man, find out they are much happier with another woman.
And I took 20 years to realize I liked girls, which compared to 40 isn't a lot but looking back, it feels like it shouldn't have taken so long lol. I do think it has something to do with exposure tho, because what made me realize it was listening to a lesbian on a podcast. I had a lot of the same opinions and feelings as her about things and it made me go "huh... Wait a minute." And then all the pieces throughout my life just kinda clicked into place, like "ohhhh that's why"