If she literally scans it with a scanner, why would it need dewarping? This is for when you use a digital camera on pages not lying flat.
If you have the option go for scanning.
Scans still benefit from cleanup, such as rotation and adjusting the levels (making everything near white perfectly white) and possibly manual cleanup (removal of specks of dust or the odd hair that was on the scanner).
They still warp, but less than laying flat on the table and it's quicker if you do all the even pages, then all the odd pages. Actually the hardest part is making the camera stable so it doesn't move when you press the button.
Lots of info on different hardware setups and scanning software here that can batch translate into pdf and different formats.
With that setup, I'd just find a sheet of glass to press the page flat. Cameras have resolution in the right ball park these days. 600 dpi across 8 inches is, what, 4800 pixels.
I remember when I was in my middle school orchestra, occasionally I'd get a piece of sheet music with this problem. If it was bad enough, it might even make it impossible to read the last few notes. If you could fix this for your wife, I'm sure her students will greatly appreciate it!
Ah that; it's a major difficulty. A problem is that not only does the shape warp, but any part of the image that is lifted away from the scanner glass, even slightly, gets blurred quite a bit.
If you have the option go for scanning.
Scans still benefit from cleanup, such as rotation and adjusting the levels (making everything near white perfectly white) and possibly manual cleanup (removal of specks of dust or the odd hair that was on the scanner).