How can I help my friend?

Hello everyone,
I have posted in this forum before and received enlightening replies for a matter that concerned myself. Now I have to ask for advice about how to help my friend who’s in a bad situation. The big problem is: Only I know it’s a bad situation. This is going to be a long story but I’d appreciate any help!!!

So we went on a holiday to Curacao together in February, where we took a boat trip. My friend fell in love with one of the guides/ “captains” on that boat. She was flirting with him so hard, always tried to get his attention. Back at the hotel, she started following him on Instagram and he instantly asked her out. He’s 41, she’s 31. They were texting back and forth the whole day and in the end didn’t go out because he didn’t reply anymore. During the next few days they kept texting and eventually met up on our last day (for about an hour). They did make out.
Back home, she was in a post-holiday depression and was only happy when he texted or they facetimed.

A couple of weeks later he told her he would come to the Netherlands for vacation and they could meet up (we live in Germany). She was soooo excited and spent hours reading about covid related travel restrictions, quarantine rules etc. He was always avoiding to set a proper date for the meetup. At first it was their plan to let him come see her, but in the end she gave in and agreed to go to the Netherlands for one afternoon. They had narrowed it down to two or three possible days and when he didn’t reply to make it safe and the days went by, she was devastated. Didn’t eat, didn’t sleep, only cried and smoked cigarettes. It was horrible to see.

I was silently happy she would finally give him up, but uh-uh.
A few weeks later she ACCIDENTALLY sent him a text and now they’re back how they were before. She’s even talking about travelling to Curacao later this year to see him.

I don’t understand. She’s not even telling me about him because I hate him for making her feel that way. I just don’t understand! Why would she want to meet him after he had ripped her heart out? WTF? Another friend of hers is on her side, she romanticizes it and approves it, even pushes her into it. WHY?????
I really don’t know what to do. I want to make her realize that she deserves better. That she doesn’t need him. She thinks she does.

Please help.