You can start by letting her pick out some big girl undies and training pull ups. What really helped my kids train was a reward jar. Everytime she tells you or goes to sit on the potty, let her pick a reward from the jar. Even if she doesnt go, still reward her for sitting on the potty. I got a jar from the dollar store and filled it with stickers, lollipoos, and other fun things kids love. It helps too if you allow her to go into the bathroom with you so she starts understanding what its for. Good luck! :)