Some people know I'm 13 because of my past questions. But I want to hide it or at least make it private. Long story short, people judge my questions by my age. I know I'm 13 and that's kind of young, but I'm more mature than most!
You know what? Don't care about what people think of your age because no one knows who you are. They have no grounds to judge you and this website is about answering questions and helping people so any age can do that. Don't be ashamed of your age, if you're more mature than that then that's great! Don't worry too much about what other people think, screw them.
Are you that young girl who just joined? I know it sucks and you will get shit from some of us here, but, even through your tone, we can tell that you are different and a bit more mature for a 13-year old. Be yourself. You will get more shit if you lie about your age.
And, no, I don't think you can make your age private. Maybe if you ask a question anonymously though. I've never asked a question or replied anonymously, so I am not 100% sure, but it does look like an age range is given for anonymous questions like this one.
Be proud of yourself, being 13 and having something to say - If someone says she is 13 and should be ignored, I wouldn't be interested in their opinion, they are the ones acting like a 5 year old, be glad you are more mature than them.
I think it is better to have your age known for it allows you protection from fellow GAG members. I have no doubt you are very mature for your age but you need to be very wary on the Net of predators that will try to exploit you and hurt you