I think I tried one a fair while ago, she totally rejected it, then as she was approaching 2 I figured I should prob try again so we bought her the Peppa one and I did BT routine as normal, was breezy about it, handed her the cup and said "oh look at your new cup for milk it's got Peppa on!" and she took it fine. Like I say it does have a valve so I think that helped, that the milk wasn't just flowing out, I will need to get rid of that at some point...!