Is it important for babies to know how to use a sippy cup? We've tried nearly every sippy cup going, and Ella started to get the hang of drinking water from the tommee tippee one, for 6 month + babies. She refuses to now! As soon as she sees it coming towards her she gets distressed and pushes it away. So we've tried letting her drink without the lid on and she loves it. Is it okay for her to do this (Obv supervised) or does she need to get the hang of it with the lid on?