Forget about her age or what's happened in her past and your situation and don't think about what you think she *should* be able to do....work on the dog you have in front of you right now. Make small goals so that you can see progress, take baby steps. You cannot expect a dog that's been living outside to suddenly be doing obedience and heeling on a leash. She's going to need the treats for a while and if that's the reward she's working for it will need to be slowly faded away. But more importantly you need to establish a relationship so she WANTS to work with you, treats or not, and that just takes a lot of time.
I would sign up for a basic obedience class. If you're getting frustrated, you'll benefit from the help of a trainer who can observe and help you make some realistic goals, get the ball rolling as far as progress.
There's no reason she can't enjoy your company and learn obedience even living in a kennel, provided she's getting enough interaction, physical exercise, and mental stimulation.
Coke (All-American 7/7/06)
Nikon (GSD 9/7/08)
Indy (All-American 5/10/12)
Legend (GSD 10/22/13)
Rainbow Bridge Kenya (GSD)