Good for you wanting to help out your Aunt, family and most of all the dog.
Look into a Gentle Leader it will allow even your aunt with back and should problems walk the dog. Here is the website
http://www.gentleleader.com/pages.cfm?id=17

I would recommend clicker training for the fastest and best results for your training. Here is a really great website
http://www.clickertraining.com/home/

Good luck with your training.