I know this may seem insulting and I do NOT mean it that way but what about your mom reading her manual? Usually the machines today have very good manuals that will introduce you to your machine. The way I learned to use my TOL Bernina (way back when), was using the manual. Best of all the manuals today seem much better than 30 years ago.
Another thing is the internet. Has your mom visited here:
http://www.husqvarnaviking.com/media...ingroom_us.asp
This is Viking's instructional video series. Then you have Youtube.com. If your mom just starts to use the machine to make something as she has questions say on a zipper insertion or a buttonhole etc... she could search Viking Ruby Buttonhole and I'd bet she get enough information to get close.
Finally joining a board like this to ask any specific questions. This is an unusually positive and supportive group I bet she'd get almost immediate help/answers.
But the big point is to tell her she can't break her machine and to just use it.