Start again when she herself indicates an interest in learning to potty train. Not every kid wants to know about this at 2, or even at 3, and you will just cause her grief and frustrate yourself if you try too early. And so what if your cousin's daughter was potty trained at 1 and now plays the violin.
AnnieBrooke is completely right. My 3 year old isn't potty trained yet, and its nothing to be concerned about. They do it when they are ready and they want to.