I love you, and oh I am planning on a garage sale in a couple of months, if you want to put stuff in let me know. I call you then because thats business.
My first comment is this: I'm so sorry, I can't even imagine what it's like to be shunned by family.
My second comment: Is it by chance possible to start a small business with your mom? Perhaps a small ebay business selling her favorite crafts, hobby products, etc?
I don't think it would take much of a loophole to get your mom back in your life and in doing so it may get her to realize what an utter shame the shunning policy is.
Who cares if the small business didn't make any money or even failed in 6 months. By then, your mom would be accustomed to the contact and not want to give it up.