Bathrooms are SO MUCH FUN!!! Going potty is SO COOL!!! When we go potty, Mommy gets SO EXCITED AND DOES THE I-WENT-IN-THE-POTTY DANCE!!! I get to use my really cool soap and my very own towel that Mommy let me pick out at the store!!! Then, I get a treat! Going in the potty is REALLY, REALLY better than going in my pants. I also get to wear the panties I picked out myself!!! I LOVE being a big girl!!!
Going in the pull-up/diaper gets zero response and nothing fun happens. I have to have my diaper changed in the same place my baby brother gets his changed. Diapers are for babies. I'm not a baby -- I'm a BIG GIRL!!!
(BTW, Supernanny doesn't like pull-ups: she says diapers or big kid pants. I may do that on my next one. Also, diapers are a lot cheaper and less fun-looking than pull-ups. and cheaper. a lot cheaper. and less glamorous. and cheaper.)
Also, there are books and even videos. They all talk about going potty and being big kids.
Just inundate her. The thing that finally convinced mine was that she knew she couldn't go to preschool until she was trained. Very big impetus!!!