A.T.
I had the same issue with my son. A friend of mine told me how she would take her child's diaper/pullup/underwear off and only put a long t-shirt on the child. It took several days, but it worked. So I decided to try that with my son. I was terrified that the carpet would be ruined since we lived in an apartment, but it was my last hope. I was so frustrated and so was he. (We sat for hours in the bathroom to no avail.) I told him he couldn't put on a pullup or underwear until he went #2 in the potty. I would put a pullup on at night and almost immediately he would go. I knew he knew what he was doing. One day he did make a mess on the living room floor and it scared him to death. After that, he held it in for a few days and then a couple days later I was in the kitchen and I heard him run in the bathroom. I waited a few minutes and soon he called me in. He had done it all on his own and he filled the toilet with all he had been holding in. We had a huge "potty party" and he was so proud. After that, he only had a few accidents and has been great every since. I don't know how it would work for a girl, but it might be worth a try.