I think my colleague's advice is sound. In addition, you should have your friend call the local D.A. and report the neighbors for elder abuse. If neither of these steps work, have your friend contact the local legal aid society to see if she can get free or low cost legal assistance. She should also exhaust all possibilities of help from family and friends.
Call the city. Inquire as to whether a permit was pulled before building. Make the city tear it down and charge the neighbor since it encroaches on her side of the property.
The above information does not establish an attorney client relationship nor is it meant to provide legal advice.