Instagram does have rules for people with an age limit, and if you do, then it would have to be a joint account with an adult, say like, you are there to supervise her every moment on instagram. That is the only way I would do it, else, no way, for any child that young. And once they are hooked like people say, it will just destroy her social life, off the web, as she will be just an introvert. My kids got on the computer too young, and they are just fat and lazy, and spend all their free time doing video games on the web, 98% of the time. It was their mother's own doing, as she was too fat and lazy to go anywhere with them. So, not all mom's do the right thing. Time for you to step in as a father, if you have the chance to do so. My ex, would not even listen to what I thought was right for them. She was in her own world, that is why god punished her.