I am very sorry for you loss. I had to get a travel permit for a relative's cremated remains in December. It was a process. You need a death certificate and a proof of cremation.
Fax the documents to these folks:
St. James Health Department
Ph: 1-876-979-7820-4
Fax: 1-876-979-7802
Email:
saintjames@wrha.gov.jm
St. James Montego Bay PO St. James, Jamaica WI
There is a cost of around US$60. The hard part is you must have the original documents issued by the health department with you when you arrive in Jamaica. A cab driver friend paid the fees and picked up the documents.
When we arrived in Jamaica I ran outside and got the documents. Then the hard part - swimming upstream against airport security while a family member was discussing the matter with security. They will not let you take the remains out of the airport without the permit. Airport security took the documents back to my family member and all was good. Had a beautiful sunset boat ride and we placed his remains in the sea. PM me if you have any questions.