R.R.
I answered a similar question a few hours ago so am going to copy & paste most of my answer:
OK, I was skeptical but I tried the advice on this site:
http://www.rogerknapp.com/medical/pottytrainingrefusals.htm
and it worked : )
I started training my guy at 22 months and his main thing was he wasn't going to poop in the potty, he would do it if and when he chose, once on the carpet, ewwww, and he was becoming a master at holding it, not good! I tried stickers, a reward chart, Matchbox cars, Thomas the Train underwear, even Jelly Bellys, (and I am against using food as a reward, lol) and none of it worked more than a time or two. We stopped training twice and then I read the suggestions on this site and put them to use...the key was the "power incentive."
Basically, all rewards work for some children, none of them work for all children, and for some meeting the goal of being potty trained is the reward in itself. So what may work for other parents won't necessarily work for you and your daughter. You, as her parent, have to find THE one "power incentive" that will motivate YOUR daughter, not another child. For my guy it was a "Toy Story" DVD. I owned it (otherwise, per the advice, he would have lost interest in complying with training as he would have attained the material prize) and when he pooped in the potty he was allowed to use it 30-60 minutes, and only then. I kid you not, within a day and a half he was running to the potty to poop so as to not go on himself! This was shortly before he turned 2.5.
Adding for you, M.:
Your daughter isn't emotionally ready. This doesn't mean you can't try to train her, just that it will take longer, maybe much longer, until her emotions catch up to her physical readiness. She is saying she's a baby, so go along with that. Tell her than babies wear diapers/pull-ups, and she will wear them as long as she poops on herself. Send her in pull-ups to school until she desires to be a big girl. Point out the things she is missing out on by still being in the 2 year old class, give her more responsibilities at home (it all works together to help them mature) and find her "power incentive," I can't stress that enough.
Then relax, because she has learned she can control her body and it's functions, no matter how much you want her to poop in the potty she is going to hold it until she is good and ready and feels she has a reason to stop being a baby.