You Do Need power plug adapter while traveling from Jamaica to Saint Kitts and Nevis.

Here is Why You Need An Adapter

The outlet and plug type used in Saint Kitts and Nevis are D and G and in Jamaica are A and B. This is how they look like.

Jamaica

In Jamaica, outlets of type A and B are in use.

Type A

Type B

Saint Kitts and Nevis

In Saint Kitts and Nevis, outlets of type D and G are in use.

Type D

Type G