Jazz/ballet dancers: is this a realistic goal? Be honest!?

If what you said is correct, you're extremely good for only dancing for a year. If you've improved that much that fast, I think you can easily achieve your goal. Since you seem to be good at pirouettes and piques, work on your fouttes, a la secondes, and leaps (grande jettes). After you become better at those, start working on your pirouettes and piques. Before you begin working at triples, make your doubles perfect. Same with singles into doubles. About grande jettes (leaps), before you can get a great leap, you need to get a great split. Stretch on the floor in all of your spare time. Go down until it hurts. That's where you need to hold it. When leaping, make sure to stay lifted. Don't lean forward, and give your back leg as much attention as your front leg. For your turns, the most important rule, SPOT! Also, to stay balanced, feel the ground. Dig into it on the highest releve you can get. Remember that June is a long time from now. You have plenty of time to work on your technique. Good luck! Hope this helps!