How many years are left on the existing mortgage? You need to talk with an attorney that handles real estate and is well versed in all the issues in todays real estate market. Your mom may have many options, even with bad credit. However, you need to have an eye to eye with a real estate attorney to make progress.
Attorney Brynteson is correct. It is vital that your mother retain an experienced New Jersey real estate lawyer to work with her on the re-fi and, possibly, any issues that still need to be addressed in your father's estate. Good luck to you.
This information is presented as a public service. It should not be construed to be formal legal advice nor considered to be the formation of a lawyer/client relationship. I am licensed in Connecticut and New York and my answers are based upon the law in those jurisdictions. My answer to any specific question would likely be different if I were to review a client's file and have the opportunity to interview the client. Accordingly, I strongly urge you to retain an attorney in your jurisdiction with respect to any legal matter.
Both counsel are correct. You need to contact a real estate attorney and possibly a probate attorney to address the issues, review the documents and advise you on a course of action.