First off, there is no time or age that you are supposed to start pointe. It all depends on you and how strong your feet, ankles and legs are. Just because you are good at ballet doesn't mean you are ready for pointe.Too may young dancers jump into pointe work too fast and the result is sometimes career ending. The first thing is generally age. It sounds like you are old enough to where the bones of your feet are pretty much set and there is no risk of causing serious malformation of the bones. Next, and this is a hard one because I have never seen you dance, is the strength factor. Pointe work is extremely difficult. It requires tremendous strength not only in your feet but also in your ankles and legs. While you will build most of this when you start on pointe, there has to be a base strength. Your teacher will know better if you possess this. Lastly is technique. Again, your teacher can better evaluate you on this, but there needs to be a good base to grow from. Pointe shoes can cause serious damage if used too early or improperly. Your foot has to be able to support your entire body. I have seen horrible injuries from improper technique. This is a very exciting step, I know, but please take it slow and talk to you teacher about it. Take it from me, they are the thing every young dancer can't wait to get into, and the thing every professional can't wait to get out of! Be smart and listen to your teacher. If she is a good one, she will guide you down the right choice.