How to Screen Mirror from iPad to iPad (or iPhone to iPad)
There is a way to do this. Both IOS devices must be running the app ApowwerMirror and be on the same Wifi network.
iPad Pro 12.9-inch, 3rd Gen, Wi-Fi
No.
There has never been a way to do anything between two iDevices, ever!
That includes any type of remote controlling or screen mirroring between iDevices.
This is the way it is because of the way Apple implements iOS security on all iDevices.