I think you've received some good advice. Getting rid of the pull-ups and taking her to the potty about 20 minutes after she eats are both great ideas.
I would also take her a couple of minutes after she wakes up- in the morning and from a nap. After she wakes up, talk to her for a minute, (tell her good morning, etc.. give her a chance to wake up) and then take her. My son sometimes needs a couple sips of a water before I take him potty, but he usually needs to go once he's awake.
I would also set a timer for her once she's on the potty. Since she's used to being on the potty for quite awhile start with 20 minutes or so (longer if you think she needs it), and gradually decrease the time to something more reasonable, like 5 minutes (or less). So that she understands it's not a play time.
I have a potty party with my son when he goes on the potty. I say, "Yea, you did a good job!" I clap my hands and he claps too. I help him finish up and give him a big hug. We haven't had to use treats -yet- but any kind of reward that you give her if she goes is going to help motivate her to keep going.
Also, I wouldn't let her stay on the potty after she goes. Once she goes, give her about a minute to make sure she's done and if she doesn't show any indication of needing more time I would help her finish up. Have a party, tell her she did great, ask her if she wants to get her underwear on by herself or does she want your help. Ask her questions that deal with things she needs to do once she's done. She sounds like the type of kid that would never tell you she's done, so don't give her the chance to tell you she's not done, just direct her to what big girls do once they're done (wipe, pull up panties, wash hands). She may not like the new potty procedures right away, but if you're consistent she'll get used to it. I hope I haven't said too much. If you are still reading- bless you! (I do understand that all kids are different and some are much more strong willed than others, so if this doesn't help you at all, then I wish you luck finding something that does and I hope that your sanity stays in tact in the mean time!)