Hey friend!
I started teaching in grade nine RCM, actually I was just starting it. I was 19 then. What I did was teach out of my home on my own piano, so no teacher could say yea or nay. I also started only teaching beginners, but you could start more advanced because you are working on your ARCT. Be professional, but also be upfront about your age so they know. Say, "I would love to teach your daughter. Here are my qualifications (present grade, theory completed, years of playing, accompanying, ect.). I want to be upfront about my age, though. I am 15. If you are uncomfortable with that I understand." My clients actually wanted me BECAUSE of my age. They wanted someone their kids could relate to. This has been told to me twice now I think.
As far as getting your teacher's ARCT, you are too young for that the OLD way. You had to be 18 to receive it. This is still in effect until Sept. of 2009, but the NEW way is also just now in effect. The new way, which will replace the old way allows you to have part of your ARCT in grade nine. It has 3 levels. Each level has three parts. A written exam, a practical exam (or a grade 9, 10, or ARCT certificate depending on which level), and a viva voce or teaching part. You can start with your first level already. You already have your grade 9, so just do the written and the viva voce part and you are suddenly "qualified" regardless of age. You can't skip parts though. So even though you have your grade 10, you still have to do the other 2 parts of the first level. The viva voce part involves "teaching" the examiner up to grade 2 I think. You learn some grade 1 and 2 pieces that they can pick from. And you take a couple beginner books, like Alfred or Bastien and discuss, contrast, and compare them, the pros and cons, and whatnot. You also bring some samples of ear test books, finger exercises, ect. Be prepared to answer questions like, how would you teach finger, wrist, and arm staccato to a child x amount of years old? Which would you teacher first? These are just suggestions though. You would really have to get the syllabus that has exactly what kind of questions you need to be able to answer. Eventually if you want your full teacher's ARCT, you will have to do these 3 levels. The good news is that you can start now. They changed it so people like yourself can feel qualified even if you are still working in your own grades. I haven't done these yet. Actually, I'm hoping to start and finish my performer's and teacher's ARCT BEFORE sept. 2009 so I can do it the old way because it's less exams that way with only one level.
Mind you, my one exam will be tougher to prepare for, than for individual levels, but I like the idea of getting it over with in one shot. You may want to do this, too. You have JUST JUST enough time after you turn 18 to do it the old way. It is a couple hundred dollars cheaper as there is only ONE set of exams. One big written exam, one practical (or just show them your ARCT certificate and you're good to go), and one viva voce. The viva voce covers beginner to grade 8 the old way. The new way does beginner to grade 2. Then grade 3 through 6 or 7 I think. And the last set is grade 8ish -10. I DO NOT like this new way for it is TONS more work. You have to have a full exam repertoire prepared for each grade at first class (80%) standard. That would mean in the last level I'd have to have my grade 9 and 10 and even grade 8 I think, FULL repertoire ready at exam standard. That means a list A B C D for grade 9 with studies, and A B C D E with studies for grade 10 and then ABCD and studies for grade 8. And you don't know what they will ask for. Can you imagine having to relearn all the repertoire and keeping it all ready at once at those levels??!!!!!!!!

Take my advice and make sure you get in the OLD way before it is cut off. I mean, yes, you are perhaps "more" qualified the new way, but REAL qualifications don't come from a piece of paper. They come from EXPERIENCE. Which is why after this very long rant, I say yes, start teaching now even if it's just out of your living room. Explain to your teacher that you wish to take the teacher's ARCT under the OLD syllabus and thus, only have a few years left to do it. In this syllabus they recommend (as do I, but it is not "manditory"), 2 years of teaching experience. This is to prepare you to answer intelligently a 5yo who says, "what do those pedal thingies do, and what are they called?" It prepares you to be ready with answers to questions like, "what are some of the main teaching challenges with such and such an age group."
Tell your teacher that to be adequately prepared, you would like to follow RCM's advice in their syllabus and get a couple years teaching experience, and could you please try teaching some beginners real pieces at least? If you express your deadline, and your reasons for wanting to teach now in a professional way, she should take your seriously. If she tries to sell you on the NEW teacher's ARCT, explain that it takes alot more exams and money, and tell her that true qualification is in EXPERIENCE not only a piece of paper. Tell her that you will do it the NEW way if the OLD way does not work out for you, but that you would like to try it this way first. If she doesn't respect that, take your practical from her, but get another teacher to help you work on your teacher's ARCT. The only thing with the old way is that the 3 exams must be taken within TWO years of each other. So make sure you time it so that you finish your performer's ARCT withing 2 years of doing the written and viva voce. I'm doing my written close to the actual date of my performer's exam and the viva voce HAS to be done after because the syllabus says that if you are being let out of taking the practical part by showing them a performer's ARCT then the viva voce must be done after you already have the certificate. Or something like that. I forget exactly what the rules are. I just remember that I need my performer's first. IF you want to get your's under the OLD syllabus, get a teacher that is very familiar with the process to go over the syllabus with you. My teacher and I spent a whole hour just figuring out what order to do the exams in to be "legal." If you do your performer's first, you are safe though, for sure.
Sorry, that's alot of food for thought! If anything is unclear, pm me, okay? I just remember you saying you wanted your teacher's ARCT as well, so I thought I'd give you the heads up on the OLD and NEW ways because you and me are some of the few people that are in the right place at just the right time, so we can pick which we want! OH!! And do your level 5 theory as fast as you can too, because I'm almost certain you need it for your teacher's and performer's certificates which they only mail out in JANUARY. With the time limits closing in on us, you don't want to not finish your ARCT on time just because you did a history 5 the following June which would hold your certificate back till THE NEXT January.
If you feel overwhelmed with all this, know you are not alone! I'm pushing the deadline and going as fast as I can too. I'm pretty sure I'll make it though. I'll do my grade ten this June (and hopefully pass, but even if I don't I'm still gonna start working on my ARCT stuff, so I'm not behind if I need to wait 6 months to retake the grade 10). Then I have 2 years to do my performer's ARCT in, which I think will be good. Even if I fail it at the end of 2 years, I still have time to retake it. So worse cause senario 2 and a half years, and then I'll so my teacher's written somewhere near the end of that. Then I have 6 months to do my teacher's viva voce in. Yuk! That's the only tight part of the plan. I'll just have to pass it after 2 years, and then have a full year to do the viva voce in. So if I do that I'll JUST make it. You have a head start on me though so you should be fine. The only thing that could mess you up is your level 5 theory, so I'd do that ASAP so it's out of your hair! JMO though.
I'm gonna stop typing now cause it's taken me almost an hour to do all this in, wow!
Bye Eliza!