Carnival allows children nine and older to sign themselves out of Camp Carnival. The eleven year old will be in Camp Carnival. The thirteen year old will be in Circle C.
From Carnival's website ...
Is there a teen program onboard?
Carnival offers two different teen programs. For our 12-14 year old guests, Circle "C" offers a wide range of activities from late night movies, sports night, teen disco, Karaoke, late night swimming under the stars, scavenger hunts, and many other age appropriate activities.
Guests 15 - 17 years old have a place all their own as well, it's called Club 02. This program was created so the older teens can show off their skills in fun activities like Karaoke sessions, late night dances, ping pong and outdoor sporting events like basketball.
Many of our ships feature lounges which are dedicated to both age groups. Some of these lounges feature video monitors with Playstation 2 or X-Boxes, as well as comfortable seating. High energy dance floors with state of the art lighting and sound have also become a mainstay in many of our "Teen Only" lounges.
Due to these programs onboard, it is Carnival's policy to restrict anyone under the age of 18 years old into the main disco after 11 PM. Casino guests must be 18 years of age to play the tables and the slot machines. Guests under the age of 18 are not permitted in the casino. Guests under the age of 16 are not permitted in the spa and gym. Guests between the ages of 16 and 18 must be accompanied by an adult at all times.
http://www.carnival.com/CMS/FAQs/Teen_Program.aspx
Given that both of your children can sign themselves out, they pretty much have the run of the ship, with the above noted exceptions.
If you find a shore excursion that you like for a reasonable price, then yes, it is worth it. If not, feel free to go out on your own. I have been on 14 cruises and usually book one shore excursion per port. I would say that I enjoy more than 90% of them. I have done a few things on my own also.
You will find the daily schedule on your bed each evening for the next day's activities. Sometimes the daily schedules for past cruises can be found on the Internet.
If you drink a lot of soda, then the soda card is worth it. If you don't then it is not worth it.
I was on the Pride in May 2004 when it was going to the Mexican Riviera. Here is a link to some of the pictures I took ...
http://www.cruise-addicts.com/photogallery/v/Pride+-+May+2004/
