Hi Couples do do certification. I assume you will want to do PADI Open Water.
You can save your valuable holiday by doing a "referal". Basically you do all the theory and pool work beforehand in a dive school at home. When you get to resort, you may have to do a checkout/ review in the pool ( which is a good thing ) but can be in the sea completing your course on your first day - and dive every other day if you wish. I am sure your local PADI school will cooperate with this and may even liaise with Couples for you.
Check and recheck you have all the required and signed-off referal documentation with you when you arrive at the resort.
This approach can be more expensive than simply taking the entire course at the resort or beforehand. Only you cna decide how much a couple of half day's holiday and some study/"work" on resort is worth to you.
My S/O is doing this same thing as we speak!
Go to http://www.padi.com/scuba/locate-a-p...p/default.aspx
search "Jamaica" then there is a link to do your online bookwork that is connected to the Padi shop at the resort, looks like this
Couples Sans Souci S-20168
Ocho Rios, St Ann,