M.O.
I too use the Nuby's because my son likes the soft tip. But be forwarned, they do have a tendency to leak. Bright also uses the insulated playtex ones - he seems to like them OK too, but when he was just starting out the nuby's worked well. I did see that they have soft nipple sippies in some other brands. It took him about three months to get good at it. And somedays I swear he still has a hole in his lip. Chances are, you'll go through about a thousand before you find one she likes ;)
EDIT: He did like the ones with the handles best at first...he finally graduated to the "cups" without handles at around 12 months.