Can you compromise with her and not give her so much milk? She probably doesn't really need that much milk at her age, but it has probably become more of a comfort item to her as opposed to a real need for the milk. Or you can try to get her to only have 1 at night and not during the morning. Use distraction if she asks for it? She seems to be content with water during the day so it might be easier to convince her to not have the morning one. I'm guessing too that if she is drinking that much milk in the morning she isn't having breakfast? Or at least having it later?