This avoids a dependency on the app store, complex tooling, emulators, fees, registrations, etc. It touches on many topics more practical and widely applicable than the iOS ecosystem...and a Hello World can be up and running in a few minutes. Short feedback loops are great...even for children.
A hack, no doubt, but does everything important except tick the "built an iOS app" box on a future college education.
Good luck.
function > indistinguishability
As much as I hate to say this in this over competitive world, it would look good on a resume if she could point to having an early interest in development.
Just never remind her of that fact.
Plus, you can try on device without needing to deal with tooling and emulators. And you can start writing code in-browser using using Expo snack (https://snack.expo.io)
It comes with a player though - you can create the app and play it back on your device without having to register it through the app store or Google Play.
LiveCode comes to my mind as well which is close to HyperCard/Flash, but needs programming for any interactivity...
How about an iBook if this is for Apple? IBook Author is free and allows for interactive elements like quizzes and embedded HTML pages. Pretty nifty, free, but only for iOS again.