What is it with competitive females?

She sounds really immature for her age. That must be hard to deal with but just keep trying to be the best you can be and just ignore her! Yes, a lot of women are very competitive and catty, its usually due to a lack of self esteem. She wouldn't have to act that way if she was self confident! Talking to her about it will most likely only make it worse, so I think the best thing is to ignore her and not be like her yourself.