Helen, go to Carnival.com, if you haven't registered there yet, do so now. Once you are signed in click on the drop down "CUSTOMER SERVICE" tab and select Embarkation Information. This takes you to a page that has a large square the read FUN PASS Quick Check In. Don't let that fool ya, it aint so quick,LOL. Anyway, click the tab to start the checkin, it will lead you through the process.
Before you start, here is some of the info you are going to need for everyone in your cabin.
Personal Info (full name, home address, Phone #, etc.)
Citizenship Info ( Passport Data, permanent address etc.) if you don't have passports a certified copy of Birth Certificate plus a government photo ID..i.e. drivers license.
Travel Plans (flight info{flt #s, arrival and departure times} and hotel info )
On Board epense account (Sail& Sign Card) Method of payment, etc Credit card, cash, debit card
If either of your girls are under 18, you will need a permission slip signed and notarized by birth father. If this is the case, I would call Carnival for clarification and details.
Then you can print it all out. If you need help just ask.