how old is she? it seems that once kids see their classmates riding without the training wheels, they want to do it too.
My daughter's classmate has been riding without training wheels since he was 3. I asked his mom how she did it, and she said "we took them off. he figured it out!"
So I tried that with my 5 year old daughter. maybe I should have discussed it with her first, because she was very upset with me!
i just bought a second bike off craigslist for $5 that doesn't have training wheels, and now we have one with, and one without. when she wants to give it a try, she can... no pressure. but we won't have to wait a week for my husband to take the training wheels on and off anymore!
also, let her try learning on the grass... and they sell bike riding knee pads that come with bike gloves, at walmart for like $10. then she won't scrape her hands if she falls off.
good luck!!!