Technically, a 14 year old can create an Instagram account. However, they are not supposed to according to the terms of service. The minimum age requirement is 13. If you go through the sign up process and put in a birthdate that indicates you are under 13 years old, it will not let you create an account. Many kids lie about their age and have no problem signing up for Instagram though.
If your child does have an Instagram account, there are some things you should know as a parent. First of all, there is no way to completely protect them from seeing inappropriate content or being contacted by strangers. You can set some privacy controls so that only people who they approve can see their posts and send them messages, but ultimately it is up to them to be careful about who they interact with online.
There have also been instances of cyberbullying on Instagram. If your child is being bullied or harassed on the site, you can report it to Instagram and they will take action if necessary. You can also block users from being able to view your child’s account or contact them in any way.
Overall, while a 14 year old technically can use Instagram, it may not be the best idea given the potential risks involved. As a parent, you will need to decide what is best for your family based on your own values and beliefs.