Try right-clicking on the attachment and save it to the desktop - then right-click and Rename. Change the attachment extension to xxxxxxxxx.doc and it should then open in Word. She could of course change the extension before sending it to you, or of course you could always use Open Office.
If you cannot see the extensions they will be hidden - go to Control Panel - Folder Options - View tab - and untick box against Hide extensions for known file types. Click Apply and OK.