I feel like am losing one of my friend, what should i do?

My advice to you is to sit down and have a good think about the type of people you want to have around you as friends. Friends are people who make you feel good about yourself; who really care about you and your family; are people you can trust to believe in you no matter what your cirstances. These things are very difficult for a school girl to understand but let me ure you that, in most cases, only the strongest of school friendships survive. In most cases, the friends you meet at school become a distant memory once you enter university. As you progress in life and become more mature and discerning, the friends you meet at university or college and in the workplace (in your early 20's) are the ones that will last you throughout your life. I would not be too concerned about temperamental Rosie - she sounds very immature and flighty and will hurt you in the long run. Stay friendly to her but do NOT run around after her. Perhaps you might like to send her an email or a written note saying that you miss her company and inviting her over for dinner or a movie. Once this is done, don't chase after her but, instead, wait and see if she responds. If she does not, then really she is not a true friend and there is a world of people out there just waiting to meet you and you have your whole life ahead of you.