Sounds like she has decided to serve where "the need is great". Costa Rica is a popular "need greater" destination. Usually she would have to be invited by a host congregation, but it is not unheard of for JWs to just pack up and head to places like Costa Rica or Belize. There are english speaking only congregations scattered throughout CR that have 30 to 60 publishers. Typically 2 or 3 elders. Tourist destinations are usually where these english congregations are set up. She will have a good time. Pioneer hours are simple to make as much of the territory is rural and spread out and accessible to foot traffic only.
But nearly everywhere you go, the locals are Catholic and the tourists do not want to waste their time being preached to. The adventure will be high, generally the social aspects of the congregations are high as well. Lots of "get togethers" for any and every reason.
After a while the novelty wears off. You grow weary of aros con pollo. And dealing with insects and other wildlife just becomes a pain in the ass. Most new "need greaters" last a couple of years and then head home or move on.
Theft is a huge concern too. It happens all the time everywhere in CR. If it is not strapped to your body, it will be taken.