CN: Your daughter's brain is totally cool.
As per the brain thing.. I know I'm chiming in late, but it's called egoism. It's a stage in psychological development and it's when you start relating everything back to yourself like a 2-4 year old child. It's great because it sets the stage for critical thinking skills to really develop and you suddenly can apply new events to your life and past.. which teaches you to be able to apply events or lessons to different but congruent events or situations. It develops into an Aha! moment, of sorts, so it's a painful time, but so very worth it in the end.
The brain isn't actually fully developed until about 23-25 years old, but women are socialized to make themselves seem "grown up" before that point, and are pretty good at it. Men aren't asked of the same thing, socially, but it kicks in biologically around 25-27 and that's why many women report seeing a significant change in their partners at that age.
So, I know that's long-winded, but she thinks everything is about her because her brain is telling her so, and that's natural and necessary. She is acting childish because her brain reverts back to a childish operation. She doesn't worry about deadlines because she's also in an "invincible" stage where she thinks that nothing can be denied her by the outside world (or she's not going to get hurt by the world). It's all very typical because it's physiological!
Good luck and the next time she does something that pisses you off, just say "Thank you God (if you believe) for creating such an incredible process of natural selection so that my daughter can survive in this world!" or "Thank you Darwin (if you don't believe in God) for discovering/explaining this incredible process of natural selection and our adaptation to change so that my daughter can survive in this world!"