If you want to be a nurse, then you will do it. Like everyone else has said, it is your life, your career and your decision. What are the reasons that your family and friends think your decision for nursing is not right? It is good to have support but in the end, you dont want to listen to opinions of others and base your decision on that only to find yourself regretting it years later. Shadow a nurse or start volunteering at a hospital to get the idea and feel for the environment. Nursing is a great choice because you can work almost anywhere and there is so much room for growth.
Although I am still pretty young, I could have saved myself a year or two of money if I just didnt listen to family influence. I was set on becoming a doctor, then changed to pharmacy, now I am sticking to nursing which I had originally thought of pursueing but of course parents and family had alot to do with why it took me so long to get where I am. So what you shoud do is put aside everyone else's opinions and focus on yours. They will eventually come around... =) Good luck and enjoy your senior year of hs!