BAPTISM IS THE SHUN-GUN TRIGGER that all JWs will point at you and fire without any hesitation. They are programmed and propagandized to do so. It does not matter to them about your age or anyone's age at their baptism. They will shun children -- troubled teenagers who need help! -- if those same teenagers took the step of baptism at whatever age.
If a person tries to rescind their baptism and writes to the society, they are given a huge legal packet basically telling them that they are screwed. That they accepted all the tenets of this religion and consequences. A child (nor even most JW adults) has no knowledge of all the WT legal ramifications and their duplicity if you later try to get out of your baptism.
In short, DO NOT GET BAPTISED!!!