Hiya, R.!
Not only would I provide both potty chair/child seat options like the first responder suggested, but I would also switch to only underwear while she is awake and back off on encouragement. If she doesn't even want to talk about it and you are sure she does know how to complete the task then leave her alone. Let your anxiousness fade away because this is definately one thing you cannot rush. Prompting her and asking her if she needs to go might be cramping her new found independence and she is showing you by responding the exact opposite way you desire. Maybe you can have a more positive approach if you just can't resist prompting by asking her if her panties are still clean or dry. When they are praise her and when they aren't clean her up with a simple, "that's okay, try to make it to the potty next time, though, okay?"
If she wears diaper or Pullups she knows that it is okay to poop/pee in them, so why go to the potty? She might have the added discomfort of wet/soiled underwear to encourage her, not to mention the fun of going to the store to pick out her favorite charector to wear! When my daughter soiled her panties I carefully cut them off of her because it was easier to contain the poop and dealing with trying to clean them in a sanitary fashion was waaaaay too much effort, but it also made her sad to see her favorite Curious George undies go in the trash. Please don't poop on Dora/George/Hello Kitty was our motto!
It took my daughter most of the year to finally go consistently and we still have weekly accidents. She is 3.5 years old. It is the most frustrating thing I have ever tackled, but I have kept my frustration on the inside as much as possible. I have two dear friends with children the same age who had to resort to daily Miralax(laxative)dosages because their children have pretty much rebelled against potty training and just hold it in all day to avoid the issue thus becoming severely constipated. See? It could be worse!
Let us know how it goes for you and your little girl!
J.