There are a *ton* of considerations when making a purchase like this. Are you absolutely sure that she would want a frame for a domestic short-arm machine (which is what the Viking is)? Not everyone would. Personally, I would not want a frame unless I could also have a mid-arm or long-arm machine.
There are many experienced frame quilters on the homequiltingsystems group at
http://groups.yahoo.com . You might want to ask there if this is a good idea or not.