Unforunatly MSN messenger is not very good with video confereincing in my experience , you can usually have video OR sound but rarely both, some people do seem to get it working, but internet is covered in posts from those who can't get both working
I have since used EyeChat sucessfully,very easy to install .
Skype is v.good for voice - easy to set up, plus there is now a video option too
HERE
Remote Assistance means she can request 'asssitance' from you via MSN messenger, this will cause her PC screen to be visible on your PC, and you can control her PC with your mouse/keyboard, + she gets to see what you are doing on her PC so can learn for future - v.useful for those with non technical relatives