I'm raising two girls, in almost the same way my mother and aunts raised me, with a few tweaks here and there of course. I don't want to make the same mistakes that she made and let's be clear her home life is not what it should have been, having lost her mother at an early age.
She was raised by aunts, separated by circumstances from her siblings. In essence she grew up alone. Even surrounded by people my mother held her self apart as a form of protection. My great aunts did however instill a need for excellence and ambition in her.
This she passed on to us. Her children. I now pass it on to you. My paternal grandmother did the same with each of her children and her grand children. Wanting to make something of your life and yourself is not a bad thing. It is the choices that you make in the pursuit of your goal that will be judged and deemed good or bad.
Your conscience is your guide. Use it well. That feeling in your gut when you know what you've done is either right or wrong. That's your conscience. It is instinct. Whatever you will call it. Never lose it.
Ambition is not a dirty word. It can be colored by different needs and desires, but it itself is not good nor evil. It is a word that describes your drive. Your need to be someone, to do something. It by itself is not greed nor avarice., it can be shaped by these but it is not the same thing.
Your ambition will see you through school, through a career and in fact through your family. It will be the driving force of your life. What you must do is to figure out what you want and how your propose to achieve it. Determine what is acceptable in that pursuit and what is not. Follow your conscience. But, never denounce ambition.