I feel my friend is being groomed online - WWYD

[Concernedabout]

I wrote "friend" in the topic, but we are probably not friends, only acquaintances - but due to circumstances currently spend quite a lot of time together (think like colleagues).
She is approaching 60, and she met a man online who is not yet 30, living in a different country with his wife and children. They have met in person once, on a holiday in a third country organised (and I suspect, paid for) by her.
Earlier this week, I overheard her pleading with him on the phone about something, and it was obvious from her answers that he was threatening to leave her. There's apparently a contest that he needs to enter in his home country in order to become rich and famous (and be able to divorce his wife and marry her), and she was late with transferring the contest entrance fee.
She's not vulnerable - reasonably well off, and working in a profession where sound judgment is required. She told me about this guy many times (and she is clearly extremely infatuated), but I was for some reason under an impression that she is just the OW in a more conventional story.
I don't know whether to do / say something about this or not. On one hand, not my business at all. On another hand, I feel like I am witnessing a fraud and staying silent.
WWYD?

You can say something but I guarantee she will
Ignore you or turn against you. I’ve seen it happen personally with a family member, lost a huge amount of money to someone living abroad
they met on holiday. She genuinely was in love with him, he took her for an easy ride. You could see what was going to happen a mile away.

Ohhhh poor woman. I always wonder how people fall for stuff like this! I'd probably say something. Literally every story I've ever heard like this ends with the woman broke and humiliated.

There is nothing you can do, there is no fool like an old fool. Might be worth giving SS/adult safeguarding a call beacuse I suppose it does come under financial abuse.

I was in that situation once, she was my boss!
I said nothing, I knew her well enough to know she wouldn't believe me.
Luckily another colleague told her he was probably trying to use her to traffic drugs.
I'm fairly sure he just wanted money, but the drugs thing scared her off and she cut contact.

Maybe send her a link to information online about these types of deception. There's hundreds of stories, all of a similar theme.

en.m.wikipedia.org/wiki/Romance_scam

She won't want to hear what you have to say, but in your position I would say it anyway

If you are just acquaintances, do you know anyone who is more of a friend in whom you could confide your concerns? Perhaps she would listen to them?

She's an intelligent woman of sound mind, has 30 years more life experience and has economic privilege. She's trying to buy him away from his family, I think it's exploitative and disgraceful myself.