I would suggest you look at a crf150r. You may feel like you are slightly tall for the bike but I feel that a female with little experience may only get discouraged if you hope straight onto something like a crf250r. You could race the 150 for a couple of more years and also should look into the female sections in your country as I have a feeling they allow girls to race bikes like the crf150r for longer than they do the guys. The bike would be a great starter bike for you and once you get some experience you could move on.