I just potty trained my son (will be 3 next month). First, I got the Potty Power video from the library. This was the best for motivating him to use the potty. He was pee trained pretty quickly (we had been practicing for almost a year - just when he wanted to go).
For the poop: He would usually poop in the morning, and usually when playing with his trains, so one morning I watched him non-stop (really hard for me not to get distracted). When I saw him get that look on his face, I said "you are going poopy - run, run, run to the potty." I grabbed his hand and led him to the potty. He fussed that he didn't want to go, but he came with me. I sat him on the potty (he was still fussing), and then relaxed and gave him a hug to relax him. Well, the poop went in the toilet and he was very proud - he said, "That wasn't scary!" (So your daughter may be scared, too.) It took me doing that a couple times before he could do it on his own. Actually, come to think of it, he also got diarhea a couple days later, providing him with lots of practice using the potty (plus that feels so much worse in the pants). So maybe giving her foods that loosen up the bowels so she has more chance to practice.
My son is my 4th and I still am no expert, each child is different. The rewards didn't work with any of my kids. Hope this helps.