Is this a realistic Goal? Calling all ballerinas?

I want to be a ballerina,I know I could do this. There may be thousands of girls who have this dream, but that makes me want it even more. I can dance ballet, I'll start pointe next year. I'm 14. So can you tell me is this a goal I could complete, I asked if I had the qualfications to become one, and I was basically told that my chances are slim to nothing. I know theres a slim chance, but If I work hard could | reach it?