I agree with it being a control issue AND that the diapers/ pull ups should go...
When you feel that she is really ready...
Pick a week that you don't have much going and plan on staying home...Put her in panties, make sure you have several packs... The thin ones, It may sound gross, but they let more pee thru and let it run down the legs better. Take her out side and ask her about every half hour if she's gotta go potty. If she pees on mention of the potty she should go pretty quick. :-) Shake your head and tell her things like she's a big girl and big girls go in the potty, If you go in the potty it wouldn't feel icky. Do not make it comfy for her. When cleaning her up, clean her up with "chilly" water. (Out of the tap, not mixed with warm) Also, give her lots to drink... It may take a few days, but it should help. You could also bring the little potty out side with you. Tell her that if she has to go, to sit on the little potty and her panties won't get wet/ poopy.
It may sound odd, but its not as drastic as some stories i've heard on potty training...