Is there after school or weekend Professional ballet schools?
Yes there are. Actually the JKO school for ABT has afternoon classes for their students as well as Saturdays. They do not have an academic program. However, you must audition and live nearby to make the classes. They would expect you to be there at least 3 hours a day after school every day. There may be some in England too. You should call and check. Or look for ballet academies near you and check their schedules. 45 minutes is about the time you should be spending at barre to warm up before center. I don’t see how you can get anything out of such a short class. Ballet classes should be an hour and a half long.