Coming out to my brother

[tommykaine]

Hi there, I've got something to ask...it's about coming out/disclosing

The thing is, I finally have the money to start my transition; I'm going to go to a specific centre where I'll be diagnosed with GID and then I'll finally be allowed to take hormones (it should take around 4 months, from what I've been told by other guys). I've been told it'll be sustanon, dunno if this makes any difference...

But I still live with my family.
My parents know I'm trans and aren't kicking me out, but while my father is sort of starting to secretly supporting (he recently gave me some medical tape I used for binding when I was younger and stupider. Now I know that sort of stuff is BAD for binding, so I don't really use it. But I didn't tell him cause I was surprised at the moment and really appreciated the thought, because my mother used to steal and trash it when I still used it.) my mother is rather vehemently against it.
She only supported me going to another centre because there it'd take like YEARS before I'd be allowed to go on t, and plus they asked me lots of money which in the end I couldn't afford. This centre I'll be going to now is free and uses the standard european protocol (WPATH), while the other one didn't and asked me 50 euros every two visits.

To make a long story short, she doesn't want me to tell my brother that I'm trans, like, never.

But he's 10, gonna be 11 in march, and he already noticed that I look like a boy and that other people """mistake""" me for a boy, he surely will notice me growing a beard...and this is not something that would usually happen to someone's big sister.

My mother believes that it'll screw him up if I tell him anything about my situation, but wouldn't let him believe that it's common for sisters to grow a beard and the like screw him up much more than that?!?

BTW, he already know I'm bi and he's fine with it (he was amused, mostly. At his age, he finds the idea of same-sex kissing giggling-inducing), so I don't think he's gonna have a problem with me being trans.

The main problem is that my mother will strongly oppose my coming-out to him, and I don't know what to do.
I don't want him to think of me as "his sister the bearded lady", I want him to consider me as his big brother, but more importantly I want to know what would be best for him and most fair.

Do you believe it'd be better if I just don't tell him anything? Should I do that or else it'd be detrimental for his development? Or would it be worse if I told him at such an age?

And if I should tell him, when exactly should I tell him? Before starting T? After I grow a beard? After he starts asking questions?

Please, do voice your opinion, expecially if you've ever had any vaguely similar experience.