I see the iOS version is 11.0.1. ...Is Apple's Files App installed on her iPad?

If no, download it from the App Store to see if it helps since Files links to files in iCloud. ...Not sure if it will help, but can't hurt.

Also, 150 docs is a lot. Maybe, you all are running into an issue with Family iCloud Storage Levels

MacStudio M1max - 14.4.1, 64 GB Ram, 4TB SSD; Studio Display; iPhone 13mini; Watch 9; iPadPro (M2) 11" WiFi