If she has a nvidai based graphics card or chipset -
Control Panel - Display - Settings - Advanced
Click on the graphics card tab - the nvidia properties will start up - and look for nVRotate. Set it back to 0º
If there is an nvidia icon in the system tray - you can undo the Rotate from there.
If it's a different graphics chip, it'll be there somewhere, but I can't tell you where.