Limitations on other family members affect you.

Well, if you're not an addict and you do good in real life and at school, there shouldn't be a problem. Your stepmother will be able to see that even if you play a lot, you manage to balance that out at school and all. She'll even be able to take as an example to show your brother that he needs to take life in hand and organize it. That's why his limitation to computer is needed. It's for him to learn to not abuse it. It's a good way for him to learn to adapt himself to real life too. You can never get all you want and it's a 100% positive that he will encounter situations where he is restricted.