This is something that you probably don't want to hear, but this could well be one of those "respect your parents' wishes" things... I don't know how your Mom would react if she found out that your brother had gone behind her back, but I don't want to advise it.
A better and more diplomatic thing to do would be to try and have a good, sensible talk with her about it - see what she thinks and explain why you don't agree, and maybe try to see if there's any possible workarounds. If she still says that Ettinfreak cannot have an account just yet, then she probably has a good reason and one that you should respect. She is your Mom after all. Knowing from experience what Mom's are like, she probably has your brother's best interests at heart.
Ettinfreak wrote:
Ettinfreak says: DEATH to my @#$%& sister!
... Furthermore, if he really does talk like that, perhaps he's not ready for these forums yet anyway. He'd have to learn some vital netiquette first before he'd be allowed to post.