During spring break there will probably be around 200 teens. You can call Princess and find out how many kids will be onboard. They will break it down 3-12 year olds and 13-17 year olds for you. We are sailing on Feb 25th and there are 70 teens on our cruise.
We took our teenage son on CP and 12year old daughter, we also went during a break but it was Feb vacation. Plenty, plenty of kids(teenagers) around. Would it be possible for her to bring a friend, if shes afraid shes not going to have a good time? But tell her she will love it, just go sign up for the teen center. You will never see her...Have a great time.