H.W.
When I had this problem with kids this age (when I nannied and taught preschool), there were two techniques I used, depending on the child:
1. Tell them "It's time to go to the bathroom" every 1.5 hours or so. Not "do you have to go?" but "It is TIME to go". Help the child transition away from what they're doing for a few minutes, reassure them that they can come back to their play, and that it IS TIME to go.
2. For older kids, who are especially digging their heels in and arguing about using the bathroom, I just try to be matter of fact about it, but I *do* let them wet their pants. That's the natural consequence for 'not going', right? This removes the element of power struggle; if they wet, they have to clean it up and change themselves, more or less without my help. (I do clean up after them to make sure floors are clean, but at 5 and six, there should be no reason that this is MY problem to deal with because they are being obstinate or don't want to stop playing.)
In both situations, when kids wet, I have them go into the bathroom, put a towel on the stool so they have a place to sit, and give them a plastic bag to put their wet clothes in. Once the wet clothes are off, I make sure (with very little chatting) to help them get the pee off their skin with a washcloth (or, with my own son, a quick clean-off in the tub). Then, they are left to dress themselves.
Some ways parents sabotage themselves:
1. Rewarding/punishing using the potty/wetting. This places far more importance on this than need be, in my opinion. The 'reward' is staying dry; the consequence is being wet and having to change. No need to complicate it.
2. Our talking a lot about it. Whether we believe it or not, our talking and conversations about it only encourage wetting, because we are in fact rewarding their wetting with LOTS of attention. Positive or negative, if kids find a way to get our attention, chances are they will repeat it.
My advice would be to give her back the pillow pet and just tell her: from now on, it's your job to stay dry. Then, don't engage with her too much about it other than sending her to the bathroom regularly. (Remember, don't *ask*... this is so important!) When she stops getting lots of talking, attention and concern from you, when you are matter-of-fact about it and don't make a big deal out of it, she will figure it out. Just make sure to stay out of the bathroom when she's changing as much as possible-- don't make it a bonding time.
Good luck!