Re: How will I know when she is ready?
i don't think you are doing anything wrong at all. She is role playing right now, it's important that you keep up the no stress feel of it, i wouldn't even attempt to have her sit on it without a diaper if she doesn't like it. She is at an age where it is ok for her to not want to use it. I think these days too many parents put too much ephasis on getting their kids train, kids will do it in their own time.
My first 2 kids were closer to 3 before they were fully trianed (completly out of pullups, even when we went out), my 3rd trained herself, she was about 21 months old and we had a potty for her, well one day she decided that she wanted to use the potty (the little seat on the big toilet, she doesn't like to sit on the actual potty chair), well, she peed, so i started leaving her diaper off, got her some big girl underwear, and after a few months of occasional accidents she's not almost completly out of pullups (she's 26 months), she only wears them to poop (she doesn't like to poop as it is so i'm not going to force the issue of her pooping on the potty) and if we are going out somewhere where i can't bring her potty seat and we will be out a while (like the mall or a long drive). Now even if she's got a pullup on she is reluctant to pee in it, she will go hours without going untill we get to a bathroom. So all kids are different, let her play, wait a while (a month or so) then try again to take her diaper off and have her pee on it, also try to see if she likes the seat on the big toilet better.
you can also try to get her some big girl underwear (none of my kids liked the thick training pants, so i've always used just regular underwear) see if she'll wear that.