Spend time up front thinking about the filling system she will find most helpful. Organizing it up front helps a ton. Ask other users how they structure notes.

For some reason, remarkable doesn’t do enough to help users on this regard.

Also, figure out if she will use Oct. Depends a lot on use case, but also how neat her handwriting is. I don’t bother to use Oct, as my cursive is indecipherable, even to me! So that means my only hope to find past info is a comprehensive filling system, with key info on each notebook name, and notebooks carefully organized in nested folders.

Good luck!