She had read that Puerto Rico has a mild earthquake almost every day
Well my wife works in The department of geology at the university and the "red sismica" or the Agancy that is in charge for most caribbean activity is in the same university department so we usually get the information about most of the activy in the island at daily bases.
to answer the question:
You can feel it if its something big but mostly a normal case you will not feel nothing nat sea.
As for Puerto Rico
I have live all my life here on the island and I have never experience even a little movement,
Is nothing to worry, the movement occur mostly on the ocean floor and is not true that we have a earthquake everyday and when they happen are so small you will feel nothing and are not on daily bases...