Who payed for the computer you use and the internet connection? Who's house/apartment/whatever do you live in? Who carried your ass in their stomach for 9 months? Who buys you clothes and food, and who will be there for you when you get your heart broken?
In other words, yes, she does have the right. And I don't care if you are one of those kids who worked hard for your computer in chores or at a job or something, the point is that as long as you live with her and depend on her, she can be like that damn KGB on your ass and be completely justified.