I hope you are doing good. I am flutter developer and present DSC Lead so I have experience in teaching and I also have a teaching experience in school. I can briefly tell them about most common and most useful widgets of flutter which helps in developing advance UI with animations, API integration (send and receive data to and from internet) with any type of url, storage, camera and location access, backend with firebase (database, storage and authentication), authentication with gmail, Facebook, phone, etc. push notification, Google maps integration, payment integration( stripe, square, razor pay), flutter providers and many more.
If you are interested I will provide you complete course outline in chat.