As an alternative, nonprofits like ACORN are having some excellent results, even in the final days of a foreclosure situation. Find a representative there who may be able to help at http://www.acorn.org
The bank will file for a writ of possession following the auction ...
Sometimes people are paralyzed into inaction ... a helping hand from her sister may facilitate her outcome and/or transition 8-) I wish you both well.
Depending on what is owed and what the home is worth, a, "short sale," or something along those lines may be a good solution.
Feel free to email me for more information, as I could provide much more information directly as relates to this particular instance. Thank you.
Derek Bauer, Real Estate One