Here's the other opinion: I never go back to the dealer for help. I tend to sew late at night and I've yet to find a local shop open past 6pm.
I've bought machines online and at local shops and I learn best by watching videos and reading online. If your mom teaches herself things easily, go for the machine at Hancock's. If she likes to ask lots of questions and to be shown things, then a local shop with lessons and classes would probably work better.