I would get her signed up on the homequiltingsystems group at
http://groups.yahoo.com . Lots of different setups there, plus users who can give her the pros and cons of each system. From the advice I have seen there, she really wants to take her time to research and try out a variety of machine/frame combos before making a final decision. Some of the machines have better hand controls than others, which could make a difference with her carpal tunnel.
Incidentally, I was diagnosed with severe carpal tunnel several years ago. The surgeon insisted I would be back for surgery, but I wanted to work on it myself first. I got rid of it! Wore hand braces from Walmart (kind with max support, steel in the palm side) night and day, cut my computer time in half, changed my computer setup to be more ergonomically correct, and took citrus bioflavanoids twice a day. Worked for me!