Do you mean you're 13 now or just in the dream? I know you read a lot so your imagination will be able to make all kinds of dreams so I definately wouldn't worry about it not being normal; there's no such thing as a normal dream really, take a look at my latest dream for example. And remember, dreamers are the lucky people that get to lead two lives.

You can also check out the Dream Dictionary if you like to see if anything rings true for you regarding your dreams.