I`m not certain if an individual account can have differences in screen settings, but I know that acceleration can affect the mouse pointer in some instaces - even MS admit it.
Is the Hardware Acceleration setting the same as yours? You should try this logged on to your account and then for your wife.
1. Right-click the desktop, and then click Properties.
2. On the Settings tab, click Advanced.
3. On the Troubleshooting tab, check the position of the slider.