Hi K.,
Oh I feel for you! My son potty trained about 2 or 3 months ago and he'll be 4 in July. I went through some similar things as you and finally just decided that he would be ready when HE was ready and not a second before that! I have a portable potty for him that I left in the living room for him and one day he sat down on it and went pee. It was his own choice and I praised him up and down for it. Thankfully it was a day that we could stay close to home all day and I let him run around the house naked all day. All that day he went on his potty! My husband and I decided not to put him back in a diaper, we thought that could be confusing for him. So except a pull up at nap and night time he hasn't been in a diaper since. I carried the portable potty in the car with us for about a week and as we would get in and out of the car I would ask him if he needed to go and if he said yes great and if he said no I respected that. He only had two accidents.
Even though you think your daughter is ready, she may not quite be there yet. If you ask her repeatedly to use the potty or put her on the potty instead of letting her do it, she may just dig her heels in to take back the power. You can't force them to eat or go potty! If you have a portable potty I would pull it out and set it somewhere in the house she can see it. Let her run around naked, if she has an accident it's part of her learning. Maybe just expect accidents,be calm and reassuring if she has one.
When he first trained I would carry an extra set of clothes and wipes wherever we went. For just in case.
Some people choose to use rewards or bribes to get their kids to sit on the potty. We chose not to do that. We have to trust them when they tell us they don't have to go, they need to learn their own body and if we question that then they might not trust themselves. For instance I sometimes try to get my son to go pee before bed time and nap time. In hopes of getting more than one wear out of a pull up, saves money. But whenever I do that he digs his heels right in and refuses to go even if he has to. A reminder to myself that I have to let him lead on this.
Hope this helps! Good luck to you!!
N.