J.A.
My son also has reflux and we had a horrible time with sippy cups. We had to use a straw type, Rubbermaid makes them first, then he took to the sippy. He is 2 now and he will now drink from a sippy and the starw cups but it took a long time. He even had a therapist working with him on it. I was like you and had one of ever sippy on the market and he would not drink out of any of them. One suggestion might be to put water or juice in it to get her used to it. My son would never take his milk and still will not out of the sippy, his therapist is still working on that one! Gerber is a good cup and he likes his. He tends to like the soft tip sippy cups better so see if you can find those, they were usually the starter sippys. I also took the spill proof thing out for the first few times so it was easier for him to use. I hope this helps.