I'm a medical student but in love with math since school days.

Well, first things first, she is my sister, so no one can tell better about her than I can. She has been teaching everything to me from the day I was born; hence, I'm her first student, and because of her, I could do well in my subjects. She is the best teacher I have seen; hence, she could be your best teacher too. Whatever you learn from her, you can remember it for the rest of your life.