Hi, Debby!
Congratulations on your spring cruise aboard the Disney
Wonder! The ship is fantastic, and you're going to see several ports of call full of history and adventure.
For your 9-year-old daughter, you'll register her for the Oceaneer's Club and Oceaneer's Lab. She'll enjoy both scheduled and impromptu play and activities in a secure and supervised atmosphere. She will be given a security bracelet to wear, and you will be allowed to check her in and out of the clubs with a special password for your family. As a mom, I wouldn't allow for my child to roam around the ship without an adult -- just like I wouldn't allow him/her to roam around our local mall without supervision.
For your 13-year-old daughter, I have a couple of suggestions. Register her online with
Aloft -- which is the supervised teen hangout for guests ages 13-17. However, once you're on board, take a look at both areas (teen area/kids' clubs) with your daughter to decide which one is right for her. Since she will be of the youngest in the teen area, she (and you) might decide that she's better suited for the Oceaneer's Club or Lab where her sister will be.
For Aloft, the teens check themselves in and out, and communications with them can become an issue. When we have cruised with our teen son, we found it helpful to attach a magnetic white board to the outside or inside of our stateroom door and have him sign in and out -- so that we knew where he was. Cell phone service (without an international plan) is cost prohibitive for most, and walkie/talkies can be annoying with spotty reception. You know your daughters best and know what to expect from them.
I hope this helps you plan. Have a wonderful day and a magical vacation. Bon voyage!