No. it is not. The average grown women wears an 8. About 15% of the women population wears bigger than nine so you are sure well into that. SOME men like big feet on women so do not be disenheartened.....
I'm not sure about cms, but if you are size one in normal shoes, then you should buy ballet shoes in a size 3.
girls
no
I am 12 and have size 12 shoes to , so don't worry your not the only one.
There is no "normal" bra size. It varies from girl to girl.
Size 7/12 girl shoes
it should be a 9-9.5 :)
it's around 5
yes
Age does not determine breast size. Any size is normal.
I don't know if I would say it is abnormal for a girl this age to have a size 10 shoe, though it is not common. It probably means nothing more than the girl is going to be very tall when she is done growing. Since this girl is only 11 years old and already wears a size 10 shoe, then she will face having a hard time finding shoes in her size, since retail stores typically stock shoes up to size 10. Fortunately, the Internet has made it much easier to find shoes in larger sizes for women. The link below may be of value as she continues to grow and needs larger shoes.
One can purchase size 9 shoes for girls at most High Street shoe shops. Next sell them, as does Marks and Spencer. Online, one can buy size 9 shoes for a girl from Amazon and also via eBay.