There's nothing wrong with female sex tourism, is there?
Men have been enjoying it for decades, so why shouldn't women?
Amongst white women from continental Europe, Senegal is currently a hot destination. There's even travel agencies for single women which cater to the interracial fantasies of many women. Most often, it's older baby-boomer women who go on these sex trips, though. They're divorced, the kids are out of the home, they have lots of cash to spend, and so they want to enjoy life a bit. First thing they do is go fuck poor black people.
To answer your question: sure there are Jamaicans in Jamaica. Because Jamaicans are ordinary human beings, their cocks are ordinary too. Not bigger or smaller than the cocks of any other group of men.
But the fantasy may add a few inches. And if you're into that fantasy, then good for you.
It's the same story with us, white men. Why do we love to go on holiday in Thailand or Brazil? Because we think Thai and Brazilian girls are much better in bed than white girls. Of course, they're not. But it's the fantasy which makes it so.
So enjoy your trip. I'm sure it will be worth it!