I think your explanation of Ana texting subtle hints that something is wrong via her use of Spanish is a possibility.Thinking of the possibility of Ana typing both messages under a threat. Imagine yourself in Ana’s shoes. She is abducted and threatened by a person speaking good English and probably, decent Spanish, but for whom Colombian Spanish is not his mother tongue. What would a woman do? Probably, type the messages in such a way that it would attract attention. Her family would see the accents and understand that it is highly unusual for Ana.
If so, what does Chevere stand for? (The first letters of the person’s first name?)
Another possibility could be somebody has taken her phone. They dont know alot of Spanish. So, they use a mix of literal translations from their language, Columbian Spanish slang they have heard and say, Google translate which gives correct, but perhaps stilted options.
As for Chevere....
I dont know the origins to that. Spanish has the word Caballero (literally horseman, but also means "gentleman"). I think Cheval means horse in French. Maybe Chevere is a shortened version of the French for "horse rider / gentleman"?
So... in slang "I met a nice guy"? Or.... is it something to do with goat cheese in French? Sort of like "chou" which means "cabbage", but also means "cute" or "darling".