It's not worth the risk. She needs to report it to public health and get taken care of properly. There also has been a push for rabies vaccination on Caye Caulker, so there may well be a record of this dog being vaccinated.
There has never been, to date, a known case of rabies on Caye Caulker. There has been a campaign for vaccinating dogs because it's only a matter of time until someone brings an infected animal, wild or domestic, on to the island. Many owned and stray dogs have been vaccinated.
And Noelle is absolutely correct. The vaccination programme is not because there have been incidents of rabies, but as a preventative thing. There's a good chance the dog has been vaccinated, but it's important to check. A dog biting people is also an issue that needs to be addressed.