This is pretty young for her to voluntarily drop the bottle. Since you need to enforce it, you'll have to just make her. My son had no interest in cups, so when we made the choice he needed to give up the bottle, we just took it away. Actually I was at my parent's on bed rest while pregnant, and THEY (old farmers that they are) decided he was too old for the bottle (which was OK with me, I just hadn't thought of it yet) and they took it away saying, "He won't go thirsty for long". Sure enough, he was drinking out of the cup we gave him all the time 3 days later. On the days in between, he drank a little less often and fussed, but would drink a little. He didn't drink much on the first day. I wouldn't knock yourself out on trying a million cups-she just wants the bottle. Choose a cup, and follow through! Good luck!