You can delete her User Account. You will be asked if you want to keep the user account related files (in her My Documents folder). By deleting her account you would lose the customizations she has made to her account like desktop wallpaper, start menu settings, explorer and browser settings etc. You will not lose any installed programs.
You can follow these steps -
1. Create an administrator account for yourself.
2. Log out of her account and login to your account.
3. Backup her documents (if you want). Her documents would be located in a folder like C:\Documents and Settings\[UserName]\
4. Delete her account.
You should always keep an administrator level account for yourself even if you use another standard account.
How to create, delete, disable user accounts in XP : http://support.microsoft.com/kb/279783
Edited by Romeo29, 04 November 2010 - 08:09 AM.