Straws are a great idea. Getting her to help pick a new sippy cup and to help prepare the milk? Could she help tip the powder in adn stir/shake?

Could you try a pop top type bottle. My big girls have most of their drinks out of plastic sports bottles unless we are having a meal then they use cups. I realise its still a bottle but not with a soft teat. Then when she goes to kindy she will be used to a regular bottle?