Switching to straw sippy cup?

I've been trying to switch my one year old from a soft-spout sippy (her favorite) to a straw sippy, as I know that these are much easier on her teeth. She is very interested in her new cup but just can't figure out how to get the milk out! Have any of you encountered this problem? Is there anything I can do to help her, or should I just give her time? Thanks!