Don't worry about a dive buddy. My hubby goes without me all the time and there is always someone for him to dive with. CTI has the most awesome dive staff. She will have a wonderful time.
You won't be able to make reservations until you get to the resort as they need your room number to make the reservation, but don't fret, you will be able to do all that you wish to do.
You might want to head over to the Au Naturel Thread and post your other questions. MBers there will be happy to encourage your girlfriend to try the Island. It is a freeing experience. You can find the thread at the top of this page in the blue section along with the Meet Up at Couples thread and several others. You should check them out.
Juliann & Jeff
Jamaica Soon Come