Molly seems to be a bright and motivated dog who wants to please you. I know she'll catch on and probably quicker than you think. My sister has M.S. and has used a scooter for almost everything she needs to do outside the house. It has enabled her to live a very, very active life. Some of the things she does... maybe the scooter is overkill, but then again... it keeps her from getting seriously fatigued. I think it has kept her healthier than if she insisted on using her walker for everything.
Best of luck to you.