This might not be canon to this setting, but the restriction of magic is not based on age but in front of muggles.<br/><br/>If a wizard lives in a muggle home with muggles who are unaware of magic, it is illegal to cast magic in front of them.<br/><br/>If you are a wizard in a wizard home, magic is a part of every day life.<br/><br/>Even AFTER you are considered an adult (17 in the potter canon), you can still be punished for casting magic in front of muggles.<br/><br/>A remainder- this is what I know of canon potterverse, not necessarily canon with this game.