J.P.
Hi--
She might just be a little young emotionally for potty training. Some kids just do it later. Unless you are in a situation where she has to be potty trained for daycare, I would say just let her wear a pull up and she'll do it when she's ready. With my oldest we had diaper days and underwear days until he just decided that he was totally ready and did it himself. No struggles. No reward charts. He just did it when he was ready. Once he decided he was completely potty trained within the week. She won't go to kindergarten still wearing diapers. So if you can just give her time it would be easiest on everyone. However ,if she has to be potty trained I would try the reward chart or treat system, depending on what she's interested in.
J.