Hi, B.. Years ago when my son was at the potty training age, I read a book called "Potty Training in Less Than a Day," although I may be getting some of the words in the title wrong. It is a wonderfully gentle approach which uses a drink-and-wet doll to model potty training for the child. In other words, you make the doll wet its diapers, then you make the doll "pee" in the potty, and then the child has a better idea of what you want her to accomplish. My son was in daycare at that time, as I worked about 10 hours a day, so they actually did the job for me, so I missed out on that stage of my son's life. However, at the time that book was popular, it got a lot of praise for its effectiveness. That's why I recommend it. The book gives you a way to reward the good potty behavior while not having to punish the accidents or the not understanding.
Also, keep in mind that even though the whole potty in the diapers business is unpleasant for you and your daughter, she knows very well that if she starts doing this thing by herself, she's going to lose some of your attention and time. She may not be ready to give up on that. You might try to find a way to give her attention in some other way to make up for what she feels she's going to lose by moving forward to the next stage in her young life.