Many things are possible; some are so low in probability as to not be worth the cost to mitigate.
She is planning to consult to a former employer who actually desires her service - that appears to be the extent of the use of any business entity she creates. Also, both parties have known each other for quite a long time, it seems. Therefore the chance for litigation of any sort is so low as to make $1000 or even $500 a needless expense.
I am not a lawyer and don't play one on TV, but I did do all the research and paperwork needed to form a California C corporation in 1995. Ten years later I did all the research and paperwork to dissolve it (I learned in the process that some corporations are simply abandoned; dissolution requires some individual to assume any post-corporation liability for any taxes.) Then a couple years later I did all this again to form an Oregon C corporation.
An LLC or S or C corporation isn't intended for her (or my) kind of work to protect private property from litigants, but is mostly to avoid problems with the IRS. Specifically, if Aunt Peggy contracts as a sole proprietor with her former employer she needs to make sure that the IRS doesn't decide to classify her as an employee of her former employer. If she hasn't already, she needs to read the IRS tests for "independent contractor" vs "employee":
http://www.irs.gov/Businesses/Small...ndent-Contractor-(Self-Employed)-or-Employee?
I agree with John's advice given back in post 5: whatever form the business takes (sole proprietor, partnership, LLC, or S or C corporation) it isn't worth the hassle for
small businesses to form in a different state than the one that is the "nexus" of their business. I say this even for California which I found to be incredibly business-unfriendly. State laws are generally rigged to eliminate any alleged advantage a foreign formed business entities may try to get around.
Once you've done the research, go with what is simplest that accomplishes your goal. In small businesses there aren't that many "wrong answers" when it comes to the form it takes.
All the above in my humble opinion.