I think it's just a matter of perseverance - just keep giving her the milk in a cup and do not offer the bottle as an option. Or, if she is getting very insistent, give her a choice - milk in a cup, or water in her bottle. She won't like it, but eventually she will get used to it. If she flat out refuses to drink her milk at all, don't worry about it. Just try again next time. I found with my kids that they always refused to take their milk in a cup during the day, but at night time before bed they would have warm milk in a cup. So I just stopped giving them milk in the day time and they just had the one drink at night before bed.